Answer: Meg should ask why the pavement is hot
Explanation:
Meg has already completed the first step in the scientific method which is to make an observation. The next step is therefore to ask question about what has been observed. In her case she should ask, Why is the pavement unbearably hot?
From here then she can formulate a Hypothesis as to why it is hot then she can make a prediction that is based on the hypothesis and then test the hypothesis.