Determine whether the following sequence is an arithmetic sequence. If so, find the common difference and the next three terms in the sequence. 3, 9, 37, 81, ...

a
It is an arithmetic sequence. The common difference is 6. The next three terms are 87, 93, and 99.
b
It is an arithmetic sequence. The common difference is 3. The next three terms are 84, 87, and 90.
c
It is not an arithmetic sequence.
d
It is an arithmetic sequence. The common difference is 10. The next three terms are 91, 101, and 111.