Pat earns $25,000 per year (after taxes), and Pat’s spouse, Chris, earns $35,000 (after taxes). They have two pre-school-aged children. Childcare for their children costs $12,000 per year. Given that Chris doesn’t want to stay home with the kids, regardless of what Pat does, Pat should stay home with the kids if, and only if, the value of Pat spending more time with the kids is greater than:

A.$25,000 per year.

B.$37,000 per year.

C.$13,000 per year.

D.$12,000 per year.

正确答案：$13,000 per year.