During which process are cell products expelled from the cell?

Exocytosis is the process during which cell products, such as hormones, neurotransmitters, or waste materials, are expelled from the cell. This occurs when vesicles containing these products fuse with the cell membrane, allowing their contents to be released into the extracellular space. This mechanism is essential for various cellular functions, including communication between cells and the removal of waste products.

In contrast, endocytosis refers to the process by which cells take in substances from their external environment, which is the opposite of exocytosis. Osmosis is the movement of water across a semipermeable membrane and does not involve the expulsion of cell products. Passive transport describes the movement of substances across a membrane without the use of energy, but it does not specifically pertain to the process of expelling products from the cell. Therefore, exocytosis stands out as the correct answer in the context of the question.