Answer:
The correct answer will be-when a cat naps in the sun, heart rate changes.
Step-by-step explanation:
A scientific hypothesis is a proposed statement which explains the natural phenomenon to a limited extent. A hypothesis is formed on the basis of previous research work, therefore, a hypothesis is considered educated guess.
A hypothesis must be constructed in a way that it could be testable therefore includes the variables.
In the given question, Fatima wants to develop a hypothesis related to the heart rate of the cap which could be " when cat naps in the sun, heart rate of cat changes.