Weeds affect the crop plants by
competing various resources of crops (plants) causing low availability of nutrients
The correct option is C.
Explanation of correct option:
Explanation of incorrect options:
Option A:
Weeds do not affect the crop plants by killing of plants in field before they grow.
Option B:
Weeds affect the crop plants by dominating the plants to grow.
Option D:
Weeds extract more nutrients and other resources making it unavailable for crops.
Final answer: Weeds affect the crop plants by competing various resources of crops (plants) causing low availability of nutrients.