Answer:
(a) There are five wasps at the start.
(b) The rate of change shows that there are four more wasps each hour.
Explanation:
y-intercept
The y-intercept is the value of y when x = 0.
In the context of your problem, it tells you that you start with five wasps.
===============
Rate of change
You get four more wasps each hour, so the rate of change is 4 wasps/h.