Correct order of electron donating tendency when the following groups are attached to a benzene or an unsaturated group is,

1.
Correct order of electron donating tendency when the following groups are attached to a benzene or an unsaturated group is,

1. (CH3)3C – < (CH3)2CH < CH3CH2 –2. CH3CH2 – < (CH3)2CH – < (CH3)3C –3. (CH3)2CH – < (CH3)3C – < CH3 – CH2 –4. (CH3)3C – < CH3CH2 – < (CH3)2CH –