Question

Single-celled organisms are able to maintain internal stability because they

Answer 1

Answer:

yea is a at least in my case

Explanation:

Answer 2

Eliminate B and D, not all single celled organism carry out through photosynthesis , they called singled celled organism and not work with other cell, it's either A and C, single celled organism is not a complex organism. so you can eliminate letter C.

so the best answer is A, although they have multiple organs system to maintain their internal stability.