The connections between atoms in the amino acid histidine are shown. Complete the electron-dot structure by adding multiple bonds and lone pairs of electrons. Give the hybridization on the numbered carbon and nitrogen atoms. (LO 8.4)

(a) N1 = sp2, N2 = sp, C1 = sp2, C2 = sp3 (b) N1 = sp2, N2 = sp2, C1 = sp3, C2 = sp2 (c) N1 = sp3, N2 = sp, C1 = sp2, C2 = sp3 (d) N1 = sp3, N2 = sp2, C1 = sp2, C2 = sp3