According to the author, why is animal testing deemed necessary for medical research?

The assertion that animals have shorter life spans, making them easier to study over time, is accurate in the context of medical research. This characteristic allows researchers to observe the effects of treatments and drugs over multiple generations or stages of life within a more manageable timeframe. For example, studying the long-term effects of a medication can be logistically difficult in humans because of their longer life spans, yet in animals, researchers can achieve significant insights quickly. The rapid reproductive cycles of many animals also allow for the study of genetic and developmental impacts across generations efficiently.

In contrast, while other options might present merits related to the use of animals in research, they do not align with the primary reason given by the author regarding the necessity of animal testing in medical studies.