Which of the following is true about nerve cells?

Nerve cells, or neurons, are specialized cells designed to transmit information throughout the body. They accomplish this through the generation and propagation of electrical signals, known as action potentials. This capability to carry electrical signals is fundamental to the functioning of the nervous system, enabling communication between different body parts and coordinating responses to stimuli.

Nerve cells have unique structures, including the cell body, dendrites, and axon, which facilitate this transmission of signals. The axon can be quite long, allowing signals to travel significant distances, which is essential for sending messages from the brain to various body parts and vice versa.

The other options do not accurately describe the primary functions of nerve cells. While nutrient absorption is related to cells like epithelial cells in the digestive system, energy production is more characteristic of cells in metabolic organs such as the liver. As for size, neurons are not the smallest cell type; in fact, many other cell types, such as red blood cells and bacteria, are smaller. This context emphasizes why the correct answer focuses on the defining role of nerve cells in signal transmission.