Aldehydes react with carbonyl compounds in the presence of bases by a mechanism similar to aldol condensation. Given below is the reaction of benzaldehyde with 3-methyl-2-butanone in the presence of lithium diisopropylamide (LDA), a strong bulky base, and triethyl amine (TEA), a weak base. The correct structures of the major products, I and II formed in the following reactions are respectively

A

B

C

D