Right choice is (a) Polygalacturonase
Easiest explanation: Polygalacturonase (EC 3.2.1.15 hydrolyzes of 1,4-a-D-galactosiduronic linkages randomly. Pectinesterase (EC 3.2.1.11) releases methanol from the pectyl methyl esters. Pectin lyase (EC 4.2.2.10), cleaves the pectin without the necessity of pectin methyl esterase action. Hemicellulase is a mixture of hydrolytic enzymes.