To solve this question, the user must identify the pattern in the given sequence of numbers and use it to predict the next number in the sequence.

Looking at the sequence, we can see that each number is obtained by adding 213 to the previous number. Specifically, the pattern is:

213, 426, 639, 852, 1065, ...

To get the next number in the sequence, we just need to add 213 to the last number in the sequence:

1065 + 213 = 1278

Therefore, the answer is:

The Answer is: B. 1278