12.Which of the following is CH3(CH2)4CH=CH(CH2)CH=CH(CH2)7COOH? (A)18:2 Δ9,10,12,13 (B) 18:2 Δ9,12 (C) 18:2 Δ6,7,9,10 (D) 18:2 Δ6,9