Hypotheses must be provable. If scientists cannot prove a "hypothesis" right or wrong, they need to change it to a legitimate hypothesis - something you can prove.
If it is proven wrong, they can change certain aspects of it to make a more specific experiment.
I think the answer is D. A good indicator is the resting heart rate. Exercise strengthen your heart and it makes it more efficient. The resting heart rate shows of the heart is pumping blood normally each time it contracts. Having a normal resting heart rate would mean a healthy heart.
Nucleotide is a combination of a sugar, nitrogen base and phosphate groupment
1. Paralysis that’s all I know I’m sorry