Answer:
B
Explanation:
We are given that:

Are consecutive terms of an arithmetic sequence.
And we want to determine the common difference d.
Recall that for an arithmetic sequence, each subsequent term is d more than the previous term.
In other words, the second term is one d more than the first term. So:

And the third term is two d more than the first term. So:

We can isolate the d in the first equation:

As well as the second:

Then by substitution:

Solve for x:

The isolated first equation tells us that:

Therefore:

Our final answer is B.