To study the dependant variable, a scientist must . A.
manipulate the independent variable
B.
have more than one control group
C.
manipulate the dependent variable
D.
have more than one experimental group

I think it’s A. Manipulate the independent variable, because dependant variables react to the changes of independent variables.

Afew buddies come over to your house to hang out. they notice you're struggling in school, perhaps you have to rely on to pass your class, but you can't absorb the knowledge. they could positively reinforce getting a tutor and working with you, dedicating more time to the areas of struggle and less on hanging out to better yourself.secondly, say you're the victim of bullying. you're afraid to tell an adult because of possible repercussions from the bully himself. your friends encouraging you and pushing you towards telling an adult for your safety is another example.