When a B-cell undergoes immunoglobulin class switching

A the variable region of the light chain changes, but its constant region remains the sam

B the variable region of the light chain remains the same, but its constant region changes

C the variable region of the heavy chain remains the same but its constant region changes

D both the variable and constant regions change

Answer & Explanation
Answer:the variable region of the heavy chain remains the same but its constant region changes