What is the evolution of life on land means for the future of the life on Earth?

Life on earth, in order to continue stabilization, must have ballance.

Explanation: Life on earth needs balance. Like how plants need bees and bees need plants and everything relies on the survival of these two organisms. Without bees the plants cannot fertilize other plants which means herbivores would starve due to lack of food, as well as carnivores because now their food source has diminished. Everything on earth needs one another. It does not matter whether it is a oceanic ecosystem, or a continental ecosystem. As long as each creature is there working to keep the balance, the organisms that call earth home will be able to survive a long time.

the answer is d.) homologous; have mammary glands