All cells are comprised of which of the following?

All cells are comprised of macromolecules, which include proteins, nucleic acids, lipids, and carbohydrates. These macromolecules work together to form the structural and functional components of cells. For instance, proteins serve as enzymes, structural materials, and signaling molecules; nucleic acids like DNA and RNA are vital for genetic information and protein synthesis; lipids make up cell membranes; and carbohydrates are important for energy storage and cellular recognition.

The other options are more limited in scope. Living organisms encompass entire systems made up of cells but do not accurately describe the fundamental building blocks of cells. Nucleic acids are a critical component of cells, but they are not the sole type of macromolecule present. Similarly, while proteins are essential, they also do not encompass the entirety of what makes up a cell. Therefore, the most accurate answer is that all cells are comprised of macromolecules.