Answer:
D. 21
Step-by-step explanation:
The first terms are ...
5, 9, 8, 12, ...
Each even-numbered term is 3 more than the previous even-numbered term. Then the even-numbered terms are ...
n = 2, 4, 6, 8, 10
an = 9, 12, 15, 18, 21
Victor should say "21."