Which of the following is correct with respect to `-I` effect of the substitutes? `(R=alkyl)`

Options

A. `-NH_(2) gt -OR gt -F`
B. `-NR_(2) lt -OR lt -F`
C. `-NH_(2) lt -OR lt -F`
D. `-NR_(2) gt -OR gt -F`

Answer

C

Explanation

`-I` effect increases on increasing electronegativity of atom. So, correct order of -I effect is `-NH_(2) lt -OR lt -F`.
`*` Most appropriate Answer is option (3), however option(2) may also be correct answer.