A control rod
(A) Should have small absorption cross-section
(B) Is generally made of boron, hafnium or cadmium
(C) Should have large absorption cross-section
(D) Both (B) and (C)
(A) Should have small absorption cross-section
(B) Is generally made of boron, hafnium or cadmium
(C) Should have large absorption cross-section
(D) Both (B) and (C)