Crushing strength of a first class brick should not be less than_____________?

(A) 3.5 N/mm2 (X)
(B) 7.0 N/mm2 (X)
(C) 10.5 N/mm2 ()
(D) 14.0 N/mm2 (X)

Answers: Crushing strength of a first class brick should not be less than 10.5 N/mm2.