Consider the following groups attached to benzene ring and how many of these show –“I” effect only $–N{H}_2 ,–N{H}_3^{+}, –F,-C{H}_{2}OH, –C{H}_3 , –NHCOR, –OC{H}_3 ,-OH$

Explanation: Only two functional groups from the given groups are going to show -I effect from the given groups when they attached to benzene ring and they are $–N{H}_3^{+}, -NHCOR$.