Although the diagram is not provided, I have encountered it before. The region labelled "B" is a ring with two small particles on it. This ring is the electron cloud and is where the electrons move. Therefore, it is negatively charged.
Answer:
The correct option is <u><em>A. they evolved from land mammals.</em></u>
Explanation:
The process of evolution explains how closely one organism is to another based on their common ancestors. Scientists believe that those organisms which show many similarities in their structures or functions might have evolved from a common ancestor in the past.
As in the above-mentioned question, scientists have observed that cetaceans lack gills and breath air, this is a property of land mammals. The cetaceans have fin bones which are similar to the limb bones. As limb bones are present in land mammals, hence they cetaceans and land mammals might have common ancestors in the past.
It increases the chances of lions surviving a natural catastrophe.
hope this helps :)