4. There are five different tripeptides shown below. (10 points) (at least one answer). (a) Ile-Ala-Phe, (b) Trp-Glu-Tyr, (c) Glu-Ala-Asp, (d) Trp-Lys-Met, (e) His-Cys-ArgWhich one of the above tripeptides:
(6) contain the aromatic side chain