Answer:
B. 2
Step-by-step explanation:
a1,1=1
a1,2=2
a1,3=3
a2,1=4
a2,2=5
a2,3=6
a3,1=7
a3,2=8
a3,3=9
0 years: $0
5 years: $460
10 years: $520
15 years: $580
20 years: $640
6f = 24
f = 4
I hope this help
Jacob is the faster time