The formula to calculate the specific gravity of bitumen is given by ( frac{c-a}{(b-a)-(d-c)} ). Which of the below symbol and explanations is incorrect?

• A. a weight of specific gravity bottle
• B. b weight of specific gravity bottle filled with distilled water
• C. c weight of specific gravity bottle filled with bituminous material
• D. d weight of specific gravity bottle half filled with bituminous material and rest with water