C is the answer, you are correct!
Step-by-step explanation:
8h would mean $8 per hour of yard work. H represents the number of hours and since she got $40 from doing yard work this week h would be 40 divided by 8. So h is equal to 5 hours.
It’s shown as 8h because we aren’t told how many hours she worked that week. If it was shown it would be 8 x 5.
So 8h + 5 = 45.
8h + 5 - 5 = 45 - 5
8h = 40
8h/8 = 40/8
h = 5
Hope this helped! <3