Digital notes can help save which resource?

Correct answer: Paper

The governing concept is dematerialisation: replacing a physical paper copy with a digital record can reduce the need for printing and repeated photocopying. Digital notes can be created, stored, searched and shared on a suitable device, so the most direct resource saved in this question is paper. Option A is correct. Digital devices still use electricity and their manufacture has environmental impacts, so digital notes are not completely impact-free; however, those facts do not change the direct answer. Coal, cement and petrol are not the resource specifically replaced by writing or storing ordinary study notes digitally. Responsible users should also manage electronic waste and energy use properly.