Biology

The correct answer is: B.A cell membrane is semi-permeable.

Explanation:

A semi-permeable (or selectively permeable) membrane allows certain molecules to pass through while blocking others. This characteristic enables the cell membrane to regulate the materials that enter and exit the cell, maintaining homeostasis by controlling the movement of ions, nutrients, gases, and waste products.

Here’s why the other options are not correct:

A.A cell membrane is surrounded by fluid: This is true, as the membrane is in a fluid environment (such as extracellular fluid or cytoplasm), but it doesn't specifically explain ...