The correct order with respect to –I effect of the substituents is:
(R = alkyl)

1. –NH₂ > –OR < –F
2. –NR₂ < –OR < –F
3. –NH₂ > –OR > –F
4. –NR₂ > –OR > –F

The most stable carbocation among the following is:

1.	`	2.
3.		4.

In pyrrole 

the electron density is maximum on: