Jasmine Is a Health Psychologist Who Is Interested in Experimentally

Jasmine is a health psychologist who is interested in experimentally investigating whether massages increase psychological well-being. In her study, participants are either assigned to receive one massage a week for a month or no massages during the month-long study. The independent variable in Jasmine's study is operationally defined as:

A) the number of massages one has had in their lifetime.
B) the number of massages one receives during the one month study period.
C) the number of massages one has given in their lifetime.
D) the number of massages one gives during the one month study period.