The correct option is
C ![](https://infinitestudent-migration-images.s3.us-west-2.amazonaws.com/_70f9f4ff-e845-4895-8192-49a42a32f43820191207-7897-1el5a2a.png)
Image A (Solar energy), B (Wind energy) and D (Biogas) are examples of non-conventional sources and show the extraction process. Image C (Coal) is an example of conventional source of energy and shows the fuel but not the process of extraction.