Here’s an argument (or something like one) :
(1) (Some) animals have a pre-frontal cortex.
(2) The prefrontal cortex implies self-awareness.
(3) Animals which have self-awareness are objects of moral worth.
(4) Therefore, from (1)-(3) Animals possessing self-awareness (a prefrontal cortex) are objects of moral worth.
This argument is flawed in many respects. Objectors to William Lane Craig  argue that (1) is true on the basis of neurological evidence and that WLC is not correct on this point. Whether or not WLC has revised his view is not important here; what is important here is–giving his objectors the benefit of the doubt–that even if WLC is wrong, (2)-(4) doesn’t follow. My claim, then, is that this argument is unsound.
Here are some reasons why I think it is unsound (granting (1)). (2) is not a logical entailment, it’s an inductive generalization. Even if it is a logical entailment, its hard to see how the phenomenal qualities of conscious experience result from neurological going-ons. (This is a complex debate in the philosophy of mind). Indeed, even if (2) is true–which I am still skeptical of–self-awareness, resulting from the prefrontal cortex, is vague. Self-awareness involves something like a ‘self’; if the proponent of (2) suggests that animals have a self, there needs to be some argument for it (like J.P Moreland gives). Since, at least on naturalism, this is missing, I am not sure how (2) is true. On theism, though, this can be side-stepped; God might remove qualia from the experience of animals (as WLC and Pruss note) (and so even if there is self-awareness, there is no qualia–the basic problem underlying the problem of animal pain).
(3) to my mind is the crucial premise and I regard it as false. Now, I do think that animals are–in a restricted sense–subject to being moral objects (torturing a chicken for fun is wrong); but, the problem is accounting for the moral worth of these animals. Since on naturalism human beings are animals, the problem of pain for animals extends to human beings as well. But, this is not so on theism: Human beings are made in the image and likeness of God and so enjoy intrinsic moral worth. Let me back up, though. On naturalism, there is no reason to accord self-awareness as constitutive of moral worth. If objects are reducible to their constituents on naturalism, I am not sure where value comes in. Supposing that on naturalism anti-reductionism is possible, I still don’t see how moral worth is possible. Any account of moral worth for human beings or conscious creatures would be arbitrary on naturalism–as WLC points out.
It seems to be objectors to WLC either do not give him the benefit of the doubt, or do not engage seriously with these broader discussions taking place in the philosophy of mind and metaphysics.
 This post reminds me of a time when I saw a poster at Western University with a picture of the skeletal structure of an elephant and human being to show the purported “similar (near identical) nature” of humans to animals. This is immensely weak, though; under Leibniz’s law this is false and also from the fact that “similar structure” doesn’t imply “similar nature”.
 Some objectors found here: http://www.uncommondescent.com/intelligent-design/william-lane-craig-and-the-problem-of-animal-suffering-why-its-a-poor-argument-against-atheism-but-an-excellent-argument-against-scientism/ Accessed July 20th, 2016.