Determine the first five terms of the sequence defined by the following explicit formula: an = -3n/8.
a. -3/8, -6/8, -9/8, -12/8, -15/8
b. 3/8, 6/8, 9/8, 12/8, 15/8
c. 3/8, -6/8, 9/8, -12/8, 15/8
d. -3/8, 6/8, -9/8, 12/8, -15/8