For the park's ride sign, there are two pieces we need to look at.
1) "At least 44"
2) "No more than 74"
The first piece tells us anyone more than 44 inches can ride. 45 inches is okay, since 45 is more than 44 (45 > 44 is true). 44 works too since 44 ≥ 44 is true. So you can say a person's height - h that is more than 44 makes it true, h ≥ 44. We reverse its orientation and say that 44 ≤ h.
The second piece says if you are under 74 inches you can ride. "No more than" means we don't include 74 inches but 73 inches would be fine. With symbols, 74 < 74 would be false, and 73 < 74 would be true. Using anyone's height - h - that means h < 74 is true.
Put the pieces together, and we have 44 ≤ h < 74 (choice B).