**Core Concept**
Normal sexual arousal and orgasm involve a complex interplay of psychological, neurological, and physiological processes. The process begins with erotic stimulation, leading to increased blood flow, genital engorgement, and eventual orgasm. Each phase is crucial for a normal sexual response.

**Why the Correct Answer is Right**
The normal phases of sexual arousal and orgasm include excitement, plateau, orgasm, and resolution. Excitement is characterized by increased heart rate, blood pressure, and genital blood flow due to the release of neurotransmitters like dopamine and norepinephrine. The plateau phase is marked by a sustained increase in genital blood flow and increased muscle tension. Orgasm is the climax of sexual arousal, involving a sudden release of tension and a series of rhythmic contractions of the pelvic muscles. Resolution is the final phase, during which the body returns to its pre-aroused state.

**Why Each Wrong Option is Incorrect**
**Option A:** This is a normal phase in the physiology of normal sexual arousal and orgasm.
**Option B:** This is a normal phase in the physiology of normal sexual arousal and orgasm.
**Option D:** This is a normal phase in the physiology of normal sexual arousal and orgasm.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the normal phases of sexual arousal and orgasm can vary among individuals and can be influenced by factors such as age, health status, and psychological factors.

**Correct Answer: D.**