The first four terms of a sequence are shown on the graph below.

On a coordinate plane, points are at (1, negative 3), (2, 3), (3, negative 3), (4, 3).

What can be concluded about the sequence?
The common ratio of the sequence is 3.
The common ratio of the sequence is –1.
The common difference of the sequence is 6.
The common difference of the sequence is –6.