A child psychologist argues that babies will sleep through the night better if they sleep in a dark room, and if they are bathed before being put to bed. Half the parents who volunteer for the study are randomly assigned to put their babies to bed in a dark room and the other half are randomly assigned to put their babies to bed in a room with a night light. Half of each of the two groups is also randomly assigned to bathe their infant just before bedtime while the other half of each group is randomly assigned to bathe their infants in the morning. Each morning the parents record the number of times their infant woke up during the night. In this study there is/are In this study there is/are two true independent variables one true independent variable and one quasi-independent variable two quasi-independent variables only one independent variable, and it is a true independent variable there are no independent variables in this study