Hi, there! I'm happy to help. This is a tricky one.

Ecologists say that the main barriers to continuing industrial growth in the developing nations will be __a shortage of energy, food, raw materials, and high birth rates__.
(A) a shortage of energy, food, raw materials, and high birth rates
(B) shortages in energy, in food, in raw materials, and high birth rates
(C) a shortage of energy, food, and raw materials, with birth rates being higher
(D) high birth rates, along with shortages of energy, food, and raw materials
(E) high birth rates, raw materials, energy, and food shortages

The problem is we have a list of things, the resources in short supply, and in addition to that, high birth rates.

Any list of three items should have the word "and" between the second and third items --- "X, Y, and Z" --- in this case, "a shortage of energy, food, and raw materials." Answers (A) and (B) lack this, so they are out.

Answer (E) puts all four things in parallel, implying these countries have "high birth rates shortages", whatever that might be! We don't want a list of four elements in parallel. We want the three in parallel, the three that have shortages, and the high birth rates clearly distinguished from that list of three.

That leaves answers (C) and (D). Answer (C) starts out well, but the second half "with birth rates being higher" is awkwardly wordy. It's not a hard and fast rule that the word "being" is always wrong in SC, but at the very least, it should raise your antennae and make you ask: is there a more concise way to express that without the word "being"? Here, we would say "with higher birth rates." Furthermore, answer (C) has changed "high birth rates" to "higher", using the comparative. This implies a comparison "higher than what?" That changes the meaning of the sentence: no correct GMAT SC sentence is going to have a comparative without explicitly identifying what the other term of the comparison is. Therefore, answer (C) is out.

That leaves answer (D) --- that's not exactly as I would phrase the information, but there's no grammatical error, whereas the other four answers all have serious problems.

Does that make sense? Please let me know if you have any further questions on what I've said here.

Mike