Answer: Choice A.
an = 10 + 8(n - 1)
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Explanation:
a1 = 10 is the first term
The common difference is d = 8 since we add 8 to each previous price to get the next price.
We have the arithmetic sequence with nth term of
an = a1 + d*(n-1)
an = 10 + 8(n - 1)
If you wanted, you could simplify that to get
an = 10 + 8n - 8
an = 8n + 2