The correct option is D 1- b, 2-a, 3-d, 4-c.
During digestion, complex substances like polysaccharides, proteins, fats and nucleic acids are broken down into simpler substances like monosaccharides, amino acids, fatty acids and sugar molecules respectively with the help of hydrolytic digestive enzymes. This process is called chemical digestion.
In the process of digestion, enzymes play an important role in the breakdown of molecules into simpler substances, like complex sugar molecules into simpler ones by carbohydrases and protein into amino acids by proteinases. The different smaller molecules obtained from complex biomolecules post digestion along with the enzymes responsible are summarised below:
Complex SubstancesEnzymesSimple SubstancesPolysaccharidesCarbohydrasesMonosaccharidesProteinProteinasesAmino acidsFatsLipasesFatty acids + GlycerolNucleic acidsNucleasesSugar + Bases