Devine et al. are interested in assessing whether active versus passive play causes a preference for sweet or salty foods in toddlers. they assign groups of children to either an active play, passive play, or no play group and record their food choices when presented with a variety of sweet and salty foods. in this study, is the independent variable and is the control group. active play; passive play food choice; no play no play; type of play type of play; no play

The answer is "Type of play; no play".

Type of play is the independent variable.

A variable is something you're attempting to measure. It tends to be for all intents and purposes anything, for example, objects, measures of time, emotions, occasions, or thoughts.  

The independent variable is the variable whose change isn't influenced by some other variable in the trial. Either the researcher needs to change the free factor or it changes without anyone else; nothing else in the experiment influences or changes it.

No play is the control group.

Control group, the standard to which examinations are made in an experiment. Numerous experiments are intended to incorporate a control gathering and at least one trial gatherings; truth be told, a few researchers hold the term analyze for contemplate outlines that incorporate a control gathering. In a perfect world, the control gathering and the exploratory gatherings are indistinguishable inside and out with the exception of that the test bunches are subjected to medicines or interventions  accepted to affect the result of intrigue while the control amass isn't.  

you answered your own : -/