All expenses incurred while earning revenues should be identified with the revenues when they are earned, and reported for the same time period is the:

In accounting, the matching principle states that revenue is to be matched to the expenses used to generate that revenue. 

D. Matching principle

Matching concept    D  ...............

I agree with the answer D. In terms of the Framework (IFRS), it would be matching principle, income and expenses are also discussed under the Revenue Standard.

its matching concept,,,,,D

the correct answer is Costing principle