Concept:Pawpaw leaves act as a natural meat tenderiser because of the enzyme they contain.Explanation:Meat becomes tough because of its long protein fibres.Pawpaw leaves contain papain, an enzyme that breaks down these meat proteins.Adding the leaves before cooking lets the enzyme soften the meat.Salt does not soften meat, while cutting and pounding mainly change its shape and texture.Answer:C. adding ripe pawpaw leaves before cooking.