Answer: $35,000
Step-by-step explanation:
Implicit costs can be described as opportunity cost : the cost that could have accrued to a resource owned by a firm if it had been put to another use.
Ralph could have earned $35,000 if he were employed elsewhere. Therefore, the $35,000 is the opportunity cost of owning his pizza hut. It is the implicit cost.
The other costs in the question are explicit costs.
I hope my answer helps you.