The pentapeptide leucylglycylthreonyltyrosylalanine is first incubated with FDNB. When the resulting compound is heated to 110 deg C for 24 hrs in the presence of 6M HCl, the solution will contain:
a. 1 alpha amino acid labled by FDNB and an unlabled tetrapeptide
b. 5 alpha amino acids with only leucine labeled by FDNB
c. all 5 alpha amino acids, each labeled by FDNB
d. all 5 alpha amino acids, but only alanine will be labeled by FDNB