The correct option is B Oil in a tanker
A pollutant when introduced into the environment, adversely affects the usefulness of the resources. A weed in the field, emission from cars, and chemical fertilizers sprayed on plants are all pollutants that affect the usefulness of the crops, pollute air and soil/water respectively. Oil in a tanker is not a pollutant by itself, but when it spills in water and affects marine life, it is called a pollutant.