A constant in an experiment is <u>B. </u><span><u>the quantity that must remain the same</u>. If it is constant, it doesn't change, so it cannot be variable. D makes no sense.
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I think the answer is c
Explanation:
the acceleration is constant due to gravity. and the velocity initially at zero
B) decrease genetic diversity
Genetic Diversity refers to vast differences in genetic makeup (genotype) and thus often phenotype as well. The more that extreme genes/traits are excluded in survival and/or reproduction, leading to stabilizing selection, then the more genetically "same" or similar the population will evolve to long-term. Similarity is the opposite of diversity. Thus A) is dead wrong, B) is accurate, and both C) & D) are incorrect because "rare" means not common or "extreme." And extreme traits are exactly what decrease through stabilizing selection.
Hope that this.helps! :)
she should get out of her comfort zone and try new places that could also work, like an empty class or outside