Which gland/structure secretes the male sex hormone?

Study the flow chart. Name the hormones labelled as $A, B, C, D$ at each stage.
$A \quad B \quad C \quad D$

The number of testicular lobules in each testis is...?

Given below are two statements:
Statement-$I$: The scrotum helps in maintaining the low temperature of the testes.
Statement-$II$: Low temperature,compared to the normal internal body temperature,is necessary for spermatogenesis.
In the light of the above statements,choose the most appropriate answer from the options given below.

The outer covering of the seminiferous tubule is made of fibrous connective tissue,which is called:

How much lower temperature does the scrotum provide for spermatogenesis compared to the normal body temperature?