Pesticides, though non-biodegradable, are both beneficial and harmful for agriculture. Select the INCORRECT option regarding pesticides.

Correct option is A

The Answer is option A). they reduce plant growth

Explanation:

• ​Pesticides are primarily used to control weeds, pests, and plant diseases, which indirectly help plants grow better by reducing competition and damage.
• They do not directly reduce plant growth unless they are applied excessively or improperly, which might lead to phytotoxicity.
• Phytotoxicity can cause damage to plants but is not a direct function of pesticides under normal usage.
  

The other options are correct:

•  Some pesticides can indeed reduce chlorophyll content, negatively affecting photosynthesis.
  
• Pesticides can alter nitrogen metabolism, potentially lowering protein synthesis in plants.
•  The main purpose of pesticides is to control weeds, pests, and plant diseases, making this statement accurate.