Why the answer is D please explain in steps clearly

Font 13) Sunrise Motel's cost function is given as: Y = $75,000 + $9.50X Where Y annual custodial cost x- number of guest-days of occupancy In the current year, Sunrise Motel has 8,000 guest days. In the next year, Sunrise Motel expects an occupancy level of 10,000 guest days. (All costs next year will remain in the same relevant range as the current year.) What is the expected fixed custodial cost for next year? A) $7.50 B) $50,000 C) $62,500 D) $75,000 Answer: D