Final answer:
Ejaculation occurs during the orgasm phase of the sexual response cycle.
Step-by-step explanation:
Ejaculation occurs during the orgasm phase of the sexual response cycle according to Masters and Johnson's stages of sexual response. In males, orgasm is marked by rhythmic contractions of the pelvis and accompanying ejaculation. This is when seminal fluid near the urethra is forced out through contractions of genital muscles, resulting in ejaculation.