NEET 2022 Biology Paper

Option (4) is the correct answer as acquired immunity is a specific type of defence which is not present at the time of birth.
Option (3), (1) and (2) are true statements and hence cannot be the answer.
Anamnestic response or secondary immune response is a highly intensified response due to memory of first encounter.
When our body encounters a pathogen for the first time then the body elicits the primary immune response.
When there is a subsequent encounter with the same pathogen, secondary or anamnestic immune response is elicited.