Refer to the given graph which shows the effect of pH on the activities of three enzymes, X, Y and Z.
The three enzyme samples, X, Y and Z are taken from which parts of the human alimentary canal?
| X | Y | Z | |
| A | Duodenum | Mouth | Stomach |
| B | Mouth | Stomach | Duodenum |
| C | Stomach | Duodenum | Mouth |
| D | Stomach | Mouth | Duodenum |
WHAT IS THE CORRECT ANSWER AND HOW?