Which of the following is an arithmetic sequence?

Answer:
A
Step-by-step explanation:
A is an arithmetic sequence with first term -2 and common difference 5. Each new term is found by adding 5 to the previous term.
B is a geometric sequence with first term 1 and common ratio 1/2.
C is neither an arithmetic nor a geometric sequence.
D is neither. We might call it an "alternating sequence."