Explanation
An arithmetic sequence is a sequence of numbers where the difference between consecutive terms is constant.
Let’s check each option:
B. 72, 73, 75, 78
Differences: +1, +2, +3 → Not arithmetic
A. 31, 32, 33, 34
Common difference: +1 → Arithmetic
C. 11, 15, 17, 23
Differences: +4, +2, +6 → Not arithmetic