Lymph Nodes

Q.

How many lymph nodes are there in the human Body?

Q. Assertion : Primary lymphoid organs are the places where immature lymphocytes differentiate into antigen-sensitive lymphocytes.
Reason : Primary lymphoid organs provide micro-environment for the development and maturation of lymphocytes.

1. Both the assertion and reason are false
2. Assertion is true but the reason is false
3. Both assertion and reason are true and reason is the correct explanation of the assertion
4. Both the assertion and reason are true but the reason is not the correct explanation of the assertion