Which of the following firing order may be used for an 6 cylinder engine？A.1-2-3-4-5-6B.1-

Which of the following firing order may be used for an 6 cylinder engine？

A.1-2-3-4-5-6

B.1-2-3-6-5-4

C.1-5-3-6-2-4

D.1-3-4-5-6-2

请帮忙给出正确答案和分析，谢谢！