Select the most appropriate meaning of the underlined idiom in the given sentence.His probation was extended because his performance was not up to the mark

Select the most appropriate meaning of the underlined idiom in the giv

1.	Select the most appropriate meaning of the underlined idiom in the given sentence.His probation was extended because his performance was not up to the mark
A.	lacking in maturity
B.	of the desired height
C.	up to the required standard
D.	more than expected
Answer» D. more than expected