Which of the following is true about bats?

Bats play a crucial role in the ecosystem and are generally considered beneficial to the environment for several reasons. They contribute significantly to insect population control by consuming vast quantities of insects, including many agricultural pests. This natural pest control can reduce the need for chemical pesticides, which benefits both the environment and human health.

Many species of bats primarily feed on insects, showcasing a diverse diet that helps maintain ecological balance. In addition to their role in pest control, some bats are involved in pollination and seed dispersal, further enhancing their environmental significance.

Given these factors, the assertion that bats are beneficial to the environment (A) and that many feed on insects (C) holds true. Therefore, selecting the combination of these statements creates a comprehensive understanding of bats' important contributions, leading to the correct choice being D, which encapsulates both the benefits and dietary habits of bats.