A solution of a peptide of unknown sequence was divided into two
samples. One sample was treated with trypsin, and the other was
treated with chymotrypsin. The smaller peptides obtained trypsin
treatment had the following sequences: LSYAIR, VSSK, and DGMFVK.
The smaller peptides obtained by chymotrypsin treatment had the
following sequences: VKLSY, AIR, and VSSKDGMF. Deduce the sequence
of the original peptide. Please explain step by step.

A. VKLSYDGMFAIRVSSK

B. VSSKDGMFVKLSYAIR

C. LSYAIRVSSK DGMFVK

D. AIRVKLSYDGMFVSSK

E. VSSKDGMFAIRVKLSY