Enzyme X breaks down starch in the duodenum. Equal amounts of starch suspension and enzyme X were placed into four test-tubes, A, B, C and D. Each test-tube was maintained at a different pH and temperature, as shown in the table. In which test-tube will starch digestion occur most rapidly?
- ApH 2, $20\,^{\circ}\text{C}$
- BpH 2, $35\,^{\circ}\text{C}$
- CpH 7, $20\,^{\circ}\text{C}$
- DpH 7, $35\,^{\circ}\text{C}$