Answer is clearly D.

What you can infer from the given information is that because frequency with which service vehicles pick up recyclable materials is reduced, residents have started to throw those materials for permanent disposal. Probably they don't want to store the trash in their homes for long. In a way, they are lacking motivation either to reuse those material or to store the materials for long so that the materials can be picked up for recycling.

A) The information given doesn't say anything about the size of recycling containers. so clearly this option is out of scope.
B) Its not given that the increase in the volume of material sent for permanent disposal is because of lack of awareness. Although i think this option is tempting but it is out of scope.
C) Opening a new recycling center near the residential area isn't going to solve the problem as its not recycle center that is running to its full capacity, its the landfills.
D) Correct option. It clearly provides the strategy to address what could be one of the reason why residents don't want to reuse some of the stuff they discard. Incentives would provide much needed motivation to the residents to reuse whatever they can.
E) Increase in the volume of material sent for permanent disposal isn't because of the strict restrictions on the type of materials that can be recycled. Its because of reduced frequency of pick up. So with the given frequency, transport vehicles are already picking up whatever they could.

hardik.jadeja wrote:
C) Opening a new recycling center near the residential area isn't going to solve the problem as its not recycle center that is running to its full capacity, its the landfills.

You explanation seems to be ok but still I am confused.

Here, we have two thing recycling center and landfills, which confusing me.

recycling center has landfills => ??

When we narrow down to options C & D, there is a marked difference between the two.

The thing to note is: number of trips the seervice vehicles can make is constant. And so is the amount they carry.

For going for option C, you have to make sure you know how far the present recycling centers are. Do we have this information? If we have it, then opening new centers close by might help but we have another question now. Since we cannot increase the frequency and the amount we carry, how does it help? had we been able to increase my number of trips of pick up from x to x+2, having a recycle center nearby would have helped me. The service vehicles could have gone and come back quickly to get another trip. But my number of trips the vehicle can make is limited. So it really doesnt help me even if i have a recycle center nearby.

Option D talks about decreasing the amount to be recycled itself. That being the case, my service vehicles can now pick up as much as they can and may have to do less trips. As the amount to be recycled decreases, i am still fine with my number of trips and amount being constant.

though a recycling plant might come nearby to residences, the city will have to increase the frequency to transport material.
also another problem is that the volume of disposable material is increasing

D fits the bill