Passage:
Modern livestock breeds and crop species have been bred to be highly productive, which means accentuating particular traits. Chickens have been bred to maintain a uniform size for cost-effective production, while fruits and vegetables have been bred to have thick, juicy flesh. To concentrate these features within livestock and crop populations, 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 and environmental change. Which of the following statements can be inferred from the passage? 1. Breeding plants and animals with genetically similar partners might lead to offspring more susceptible to disease. 2. Breeding chickens to maintain a uniform size leads to a shallow and homogeneous gene pool. 3. If chickens are not bred to have a uniform size, the production would be cost ineffective.

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.