Cost of goods sold is calculated:

A. Cost of production + opening stock of finished goods - closing stock of finished goods

B. Prime cost + factory overhead cost + work in progress at the beginning - works in progress closing

C. Opening stock of raw materials + purchase of raw materials - closing stock of raw materials

D. Cost of production + administrative expenses + work in progress closing - work in progress beginning

E. Opening stock of work in progress + opening stock of finished goods + works expenses - closing stock of finished goods

Answer: Option A