The correct answer is:
22.5° F.
Step-by-step explanation:
The temperature increases 1.5° per hour. From 5:00 AM to 12:00 PM is 12-5 = 7 hours. This makes an increase of 1.5(7) = 10.5°.
The temperature started at 12°F; increasing by 10.5° gives us
12+10.5 = 22.5°F.