प्राकृतिक गैस मुख्य रूप से निम्नलिखित में से किस कार्बनिक यौगिक का मिश्रण है?

Which of the following is NOT obtained as a direct byproduct/derivative during the destructive distillation of coal?

Which natural resource byproduct is a thick, viscous black liquid produced during the destructive distillation of coal?