A group of researchers conducts a study to determine if a child's performance is affected by the presence of other children.First,the children are taken to a room with no other children and timed while they complete a puzzle.Later,the same children are taken to a room with four other children and timed while they complete a similar puzzle.In this study,what do you call the length of time it takes to complete the puzzle

A)  extraneous variable 
B)  control variable 
C)  dependent variable 
D)  independent variable

The length of time it takes to complete the puzzle is the dependent variable because it is the variable that is being measured and is affected by the presence of other children in the room. The independent variable would be the presence of other children, and the control variable would be factors that are kept constant between the two conditions (such as the difficulty level of the puzzle or the age of the children). The extraneous variable would be any other factors that could potentially affect the dependent variable but are not being controlled for in the study.