A researcher is interested in the chore splitting habits of people who live together before they get married compared to those who do not cohabitate before marriage. The researcher is particularly interested in the couples who cohabitate to see if cohabitation leads to higher chore splitting. In a sense, the couples who cohabitate are serving as the _____ group and the couples who do not cohabitate are serving as the _____ group.

a)experimental; null

b) treatment; control

c)control; experimental

d) experimental; control