A Researcher Studies How the Scores Children Receive on a Spelling

Multiple Choice

A researcher studies how the scores children receive on a spelling test are affected by the amount of sugar they consumed for breakfast. She identifies a group of children and feeds half of them a high-sugar breakfast and feeds the other half a low-sugar breakfast. She gives them the spelling test three hours later. In this study, what is the independent variable?

A) the number of words the children can spell correctly on the spelling test
B) the number of children tested in the study
C) amount of sugar eaten for breakfast
D) the difficulty of the words on the spelling test