The correct answer is c
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Vitamin B12 deficiencies can lead to megaloblastic anemia, a condition where the bone marrow produces large abnormally shaped red blood cells that do not function properly. Dementia, paranoia, depression, and behavioral changes can result from a vitamin B12 deficiency. Neurological damage sometimes cannot be reversed
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.
<span>(decreased variation in tail feather color because no form of the trait is advantageous) Due to the fact that the tail color is no longer a necessity, so it will eventually stop being needed and variation will decrease.</span>
