Match the immunoglobulin class in Group I with its properties in Group II.

Group I	Group II
P. IgG	1. Major antibody in external secretions such as bronchial mucus
Q. IgA	2. Protects against parasites
R. IgE	3. Antibody that appears first in serum after exposure to an antigen
S. IgM	4. Antibody present in highest concentration in serum

A. P-4, Q-1, R-2, S-3

B. P-3, Q-2, R-1, S-4

C. P-4, Q-3, R-1, S-2

D. P-1, Q-4, R-3, S-2

Answer: Option A