Question

a cell membrane is...
not semipermeable.
a protective barrier that wraps around cells and helps control what moves in and out.
all of these.
the powerhouse of a cell.

Explanation:

Cell membranes are semi - permeable (so the first option is wrong). The powerhouse of the cell is the mitochondria (so the fourth option is wrong). The cell membrane is a protective barrier that controls the movement of substances in and out of the cell.

Answer:

B. a protective barrier that wraps around cells and helps control what moves in and out.