Which of the following is true of a cell membranes?
a. cell membranes allow all substances to pass through easily
b. it is selectively permeable so only certain molecules can pass through it.
c. it acts more like a fluid than a solid because its molecules are constantly
d. cell membranes surround all animal, plant, and bacterial cells.
e. it is a bilayer composed mainly of phospholipids and proteins

B, C, Dand E are all correct

Explanation:

Why B is correct- The cell membrane, also known as the plasma membrane, is a double layer of lipids and proteins that surrounds a cell and separates the cytoplasm (the contents of the cell) from its surrounding environment. It is selectively permeable, which means that it only lets certain molecules enter and exit.

Plants, animals, and bacteria have a cell membrane. Why d is correcect

Why C is correct- The cell membrane is not a solid structure. It is made of millions of smaller molecules that create a flexible and porous container. Proteins and phospholipids make up most of the membrane structure.

Why E is correct- The plasma membrane is primarily composed of phospholipids arranged in a bilayer, with the hydrophobic tails on the interior of the membrane, and the hydrophilic heads pointing outwards

Why A Is Not correct- It is very fragile and its role is to hold the cell together and to help control what substances can get in and out. It is partially permeable, allowing only some substances to pass through it. The membrane has a complex structure consisting of a phospholipid bi-layer and different types of proteins.