John, a medical student, is studying the physiological processes that lead to a penile erection. He learns about the role of nitric oxide (NO) and the process of vasocongestion. However, he is confused about the sequence of events that occur from the point of sexual arousal to the point of erection. Which of the following options correctly describes this sequence? Select one: a. Sexual arousal -> Release of NO -> Dilation of penile arteries -> Increased blood flow to the penis -> Compression of penile venules -> Erection b. Sexual arousal -> Release of NO -> Contraction of penile arteries -> Increased blood flow to the penis -> Compression of penile venules -> Erection c. Sexual arousal -> Release of NO -> Dilation of penile arteries -> Increased blood flow to the penis -> Relaxation of penile venules -> Erection d. Sexual arousal -> Release of NO -> Dilation of penile arteries -> Decreased blood flow to the penis -> Compression of penile venules -> Erection