The correct answer is option A- It would increase.
If food sources are added for a particular animal in a food web then its population will increase. It happens because the animal will have food in abundance so there will be no intra-specific competition amongst the animals of that species i.e. they will not fight with each other for food as a result of which their population will keep on increasing. Apart from this, more animals of the same species means more breeding which will further enhance the population of the animal. All these factors will make mortality rate as very less in comparison to the birth rate of that animal.
