Final answer:
Genetic selection improves animal welfare by altering negative behaviors (option a) and can also transform physical traits (option c) to ensure animals are healthier and more comfortable.
Step-by-step explanation:
Genetic selection can improve animal welfare by altering negative behaviors, which is option (a). This involves selective breeding processes that focus on emphasizing positive traits and reducing the prevalence of traits that may lead to poor welfare conditions. For example, selecting for chickens that are less aggressive can lead to a reduction in injuries within a flock. Furthermore, beyond behavior, genetic selection can also transform physical traits (option c). Livestock could be bred for traits that prevent painful conditions, enhance their resilience against diseases, and help them cope better with their environment. This directly contributes to improving animal welfare as the animals are healthier and more comfortable.
It's important to note that while genetic selection can have applications within agriculture, such as improving yield and disease resistance in crops (options in reference lists), the application that directly relates to improving animal welfare is the alteration of behaviors through genetic selection. Lastly, the practices of artificial selection and the impacts of genomics in agriculture establish the basis for these genetic advancements, allowing for the ethical and welfare-related considerations when modifying genetic traits in both animals and crops.