Use words to describe basic cell division

The answer for #3 is c but i don't know why

How heavy is thanos? a) 3000 lbs b) all of it c) the price of tea in china d) heavy enough

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange