Answer:
4 by wearing protective clothing
Step-by-step explanation:
Protective clothing refers to clothes that is made with a special fabric that has utraviolet protection to protect the body from sun exposure. Because of this, the answer is that the best way in which Alison and her dad can protect themselves is by wearing protective clothing.
The other options are not right because wearing short-sleeved shirts and shorts can cause serious burns in the parts of the body that are exposed, applying sunscreen with a minimal SPF won't give them a lot of protection from sunlight and hiking in the middle of the day is the worst time to expose to the sun.