A decapeptide (MW = 796) on complete hydrolysis gives glycine (MW = 75), alanine and phenylalanine. Glycine contributes 47.0% to the total weight of the hydrolysate.

M.wt of Decapeptide = 796 g/mol
Total bonds to be hydrolysed = (10 − 1) = 9 per molecule.
Total weight of H2O added = 9 × 18 = 162 g/mol.
Total wt. of hydrolysis product = 796 + 162 = 958 g
Total wt. of glycine in product = 958 × 47/100 g = 450 g
Molecular wt. of glycine = 75 g/mol.
Number of glycine = 450/75 = 6.
Hence, the correct option is A