Which of the following is $NOT$ a part of the intratesticular genital duct system?

The seminal plasma in humans is rich in which of the following?

The organs which produce gametes are called $...A...$ and those which neither produce gametes nor hormones are called $...B...$. Here $A$ and $B$ represent:

The primary sex organ in man is:

Identify the diagram given below.

Given below is a diagram of the $T.S.$ of a testis. Select the option which gives the correct identification of the function of cells labeled $A, B, C,$ and $D$ from the options given below.
$A$ - cells undergo spermatogenesis to produce spermatozoa.
$B$ - cell responsible for the development of male secondary sexual characters.
$C$ - heads of sperms remain attached to these cells.
$D$ - haploid male gamete.