The major contribution to the semen from:: (A) Testes, (B) Seminal vesicles, (C) Prostate, (D) Bulbourethral and urethral glands
Answer is B. Semen which is ejaculated during male sexual act is composed of fluid and sperm.

vasdeferens-10%
seminal vesicles-60%-mucoid consistency
prostate gland-30%-milky
so the bulk of semen is seminal vesicle fluid