Diseases present in an offspring at the time of birth are called .......?

For effective treatment of the disease,early diagnosis and understanding its pathophysiology is very important. Which of the following molecular diagnostic techniques is very useful for early detection?

Which type of disease easily spreads from one person to another?

Why are surgical instruments boiled in water before use?

The use of vaccines and immunisation programmes have enabled us to completely eradicate a deadly disease like

Assertion $A$: The spleen is a large reservoir of lymphocytes.
Reason $R$: The spleen acts as a filter of the blood by trapping blood-borne microorganisms.
Which option is correct for Assertion $A$ and Reason $R$?