Answer:
a. seminal glands and prostate 
b. bulbourethral glands and seminal glands
Step-by-step explanation:
The Three main glands for the secretion of semen are - 
The seminal vesicles, the prostate and the bulbourethral glands .
Seminal vesicle - it produce sugar- rich fluid ( fructose) which provide energy and motility to the sperm . 
Prostate gland- it help in nourishing the sperm . 
Bulbourethral gland - it secrets slippery fluid to lubricate the urethra and neutralize the acidity in urethra.