The arrangement of $(CH_3)_3C-,(cH_3)_2CH-,CH_3CH_2-$ when attached to benzene or an unsaturated group, in increasing order of inductive effect is

Question

$ (a)\;(CH_3)_3C - < (CH_3)_2 CH - < CH_3CH_2 - \\(b)\;CH_3CH_2 - < (CH_3)_2 CH - < (CH_3)_3 C- \\(c)\;(CH_3)_2 CH - < (CH_3)_3 C - < CH_3CH_2 - \\(d)\;(CH_3)_3 C - < (CH_3)CH_2 - < (CH_3)_2 CH- $