Final answer:
The sequence is arithmetic with a common difference of 2.
Step-by-step explanation:
The given sequence is arithmetic.
To determine the common difference, we can compare two consecutive terms of the sequence.
Let's consider the terms an and an+1: an = 2n + 5 and an+1 = 2(n+1) + 5 = 2n + 2 + 5 = 2n + 7.
The difference between the terms an+1 and an is (2n + 7) - (2n + 5) = 2. Therefore, the common difference of the arithmetic series is 2.