Which of the following carbanion is aromatic? (a) (b) (c) (d)

For the compound to be aromatic, there are 3 conditions which are written as follows- 1. The compound should be cyclic and planar 2. It should have conjugated ring system with alternate double bonds. 3. It should have (4n+2) electrons, where n is an integer. Only following compound satisfies all the criteria, thus it is aromatic. For option (b) carbanion, the lone pair in oxygen atom is involved in resonance. Hence, it satisfies 4n+2 rule. 4n+2=6 Therefore, n=1 Thus, the correct option is (b)