Biology

The correct answer is B.cell.

Cell is the smallest unit of a living thing that can carry out all the functions necessary for life. While atoms, DNA, and organelles are important components of cells, they are not themselves living entities. Here's a breakdown:

A.Atom: The basic building blocks of matter, but not living things on their own.

B.Cell: The smallest functional unit of life. Every living organism is made up of one or more cells, and cells can carry out all the processes needed for life, such as me...