Which of the following cell organelles regulates the entry and exit of molecules to and from the cell?

The cell membrane, also known as the plasma membrane, is responsible for regulating the entry and exit of molecules to and from the cell. The cell membrane is a selectively permeable membrane that allows certain substances to pass through while preventing others from entering or leaving the cell.

The Golgi apparatus is responsible for processing and packaging proteins and lipids for secretion or delivery to other parts of the cell.

Lysosomes are membrane-bound organelles that contain enzymes that break down macromolecules and cellular waste products.

The nucleus is a membrane-bound organelle that houses the cell's genetic material and is responsible for controlling the cell's activities.

Hence, the cell membrane is responsible for regulating the entry and exit of molecules to and from the cell.