Explain the answer....

Q. A couple have been trying to conceive a child for over a year without success. Recently, the man's doctor informed him that his seminal vesicles are defective. This means that
 
  (a) the man makes functional sperm, but they are not delivered because he is unable to ejaculate.

  (b) the man's sperm lack functional flagella

  (c) the fluid needed to lubricate the man's urethra for easier sperm travel is defective.

  (d) the man's semen lacks the fructose fuel needed for the sperm to swim.