Final answer:
The A) axon is the neuron appendage responsible for sending electrical signals away from the neuron's cell body to other cells.
Step-by-step explanation:
The appendage of a neuron that sends electrical signals away from the neuron cell body is the axon. Neurons are the primary cells of the nervous system, specialized for transmitting information throughout the body. The axon is a long extension that carries electrical signals, known as action potentials, to synapses with other neurons, muscles, or glands. This structure differs from dendrites, which are designed to receive signals, rather than to send them. An axon may be wrapped in a myelin sheath, provided by types of glial cells such as oligodendrocytes, which enhances the speed and efficiency of signal transmission.