In an Eight-Cylinder Engine, the Even-Numbered Cylinders Are on the Left

Multiple Choice

In an eight-cylinder engine, the even-numbered cylinders are on the left and the odd-numbered cylinders are on the right. A good firing order is a sequence of the numbers 1 through 8 in which right and left sides alternate. How many possible good firing sequences are there ?

A) 40,320 sequences
B) 512 sequences
C) 576 sequences
D) 1,152 sequences
E) 24 sequences