Greenville Industries Uses the Accrual Basis to Account for All

Greenville Industries uses the accrual basis to account for all sales transactions. Sales for 2018 total $560,000. Included in this amount is $25,000 in receivables from sales on installment. Installment sales are considered revenue for book purposes, but not for tax purposes. Operating expenses total $120,000 and are treated the same for book and tax purposes. What is Greenville's tax basis in the installment sale receivable?

A) $25,000
B) $0
C) $12,500
D) $120,000