Which endocrine gland becomes inactive in old age?

If the thymus gland of an infant is removed,which of the following will not form?

The thymus gland is a lobular structure located on the $A$ side of the aorta and plays a significant role in the development of the $B$ system.
Choose the correct combination of $A$ and $B$.

Where are Hassall's corpuscles found?

What does thymosin stimulate?

At the time of birth,the thymus gland is: