Cell specialization in multicellular organisms allows cells to

Think about it like this, if every human had to become a biologist, physicist, mathematician, chemist, historian, artist, poet, athlete, astronomer, lawyer, celebrity, government offical, ETC Would anything ever get done, No.

The same applies to multicellular organisms. It is unrealistic/impossible for all cells to perform all functions. But when specialized cells come in to the equation significantly more complex organs and organisms can be formed. So Cell specialization in multicellular organisms allows cells to more efficiently preform tasks.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

true skin; another name for the dermis. lies directly beneath the epidermis and is often referred to as the true skin. outermost layer of epidermis, consisting of dead cells.