What is antibody affinity maturation?

affinity maturation-

because antibodies can potentially be generated against millions of unique epitopes, the size of an organisim's genome would need to increase exponentially in order to every possible antigen- binding side.

Description
In immunology, affinity maturation is the process by which TFH cell-activated B cells produce antibodies with increased affinity for antigen during the course of an immune response. With repeated exposures to the same antigen, a host will produce antibodies of successively greater affinities.

The correct answer for this question is letter C. The focus of the earthquake is point of failure of crustal rocks where the waves originate. It is where the earthquake originates. It is also called as hypocenter of an earthquake.