Peroxidase activity is greatly affected by the pH factor. Peroxidase works best at the pH of 7 while decrease or increase in pH will adversely affected its activity. So when change occurs from a moderately acidic environment having pH near 6 to a basic environment, the peroxidase activity increases when reach to neutral but decreases when go further to basic environment so we can say that peroxidase activity greatly affected on the pH of the solution.
This question is actually incompete. There should be a graph attached. On the graph you can see that from when the ph is at 6 onwards it only decreases.
