Passage: Modern livestock breeds and crop species

Solution

Let’s evaluate each statement against what is stated or clearly implied in the passage. Statement 1:
"Plants and animals are bred with ever more genetically similar partners, leaving a shallow and homogeneous gene pool that is a poor defence against disease..."
This clearly supports that breeding with genetic similarity increases susceptibility to disease. So 1 is correct. Statement 2:
"Chickens have been bred to maintain a uniform size... To concentrate these features... animals are bred with genetically similar partners..."
This directly supports 2 — breeding for uniform size leads to a genetically similar pool. So 2 is also correct. Statement 3:
"Chickens have been bred to maintain a uniform size for cost-effective production..."
This tells us why they are bred that way, but not that production would definitely be cost-ineffective if they weren’t. This is an assumption, not an inference. Therefore, statements 1 and 2 can be inferred, making option B the correct answer.