I would say C.
hope this helps
Answer:
in controlled experiment an independent variable is systematically manupulated and dependent variable is measured ; any extraneous variables are controlled
Answer: B. Encouraging athletes to have children together
Explanation: The history of reproductive genetics is complex. During the early part of the last century, eugenics programs were popular. Eugenics is a science that deals with “improving” hereditary qualities. Positive eugenics encourages reproduction by those considered genetically superior. In Nazi Germany, “Pure Aryans” were encouraged to breed to create a superior race. Negative eugenics limits or discourages reproduction by those considered genetically inferior. In the United States, negative eugenics led to laws requiring the involuntary sterilization of thousands of people due to mental or physical handicaps. Events such as these have led people to question the value of eugenics. PF
