After a carefully investigation (1)/ we discovered (2)/ that the house was infested with termites. (3)/ No error. (4)

Options

A. 1 After a carefully investigation
B. 2 we discovered
C. 3 that the house was infested with termites.
D. 4 No error.

Answer

1

Explanation

careful will replace carefully because - careful is an Adj. and carefully is an Adv. Hence, After a careful investigation is the right usage