One theory of infantile autism suggests that _____ may be the cause of the disorder

A psychologist believes that music affects a person's mood. He has some participants listen to waltzes and others listen to military marches, and then measures each participant's mood with a paper-and-pencil test

What are the independent and dependent variables? a. The waltz music is the independent variable and the military march music is the dependent variable. b. The type of music is the independent variable and the participant's mood is the dependent variable. c. The participant's mood is the independent variable and the type of music is the dependent variable. d. The participant's mood is the independent variable and the scores on the paper-and-pencil test are the dependent variable.

According to the article Who's Old First about physical declines in old age, the question "When do we start to get old?" usually refers to:

(a) the numbers of children and grandchildren we have (b) the age at which we retire from work (c) the number of times we have changed jobs and moved (d) bodily systems which are not as good as they used to be