Which of the following is not true regarding an epidural block?
a. It affects only the spinal nerves in the immediate area of the injection.
b. It can provide sensory and motor anesthesia, depending on the anesthetic selected.
c. Intubation is not necessary because respiratory muscles are not paralyzed.
d. It is commonly used as a method of pain control during labor and delivery.
e. This procedure does not provide sustained anesthesia.