Answer: D. Hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Hypothesis A and B both are suggesting that caffeine intake is related to higher heart rate. But hypothesis B is proving it more certainly by suggesting the affects of caffeine intake on heart rate. As, heart rate of most people will be higher 30 minutes after they drink a cup of coffee is testifying the fact, that higher heart rate is related with caffeine intake.
Therefore, hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Any theory must contain a meaningful concept with new evolution to accept by the scientific community
If you have one sickle cell gene, you have sickle cell trait and you will not develop the sickle cell disease. If you inherit two sickle cell genes, you have sickle cell anemia.
Answer:
B. methane
Explaination: ...............................