A Researcher Wants to Investigate Whether Different Forms of Exercise

A researcher wants to investigate whether different forms of exercise can be used to help hyperactive children.A group of 90 children is divided into two groups according to age - those aged 9-12 and those aged 5-9.Within each age group the children are randomly assigned to one of three groups.The first group will just do their normal exercise.The second group will be given an additional exercise routine (moderate) .The third group will be given an additional exercise routine (strenuous) .At the end of a four month period parents will be asked to evaluate their children's progress.Identify the treatments.

A) Exercise,age
B) Age 5-9,age 9-12
C) Normal exercise and age 5-9,additional exercise (moderate) and age 5-9,additional exercise (strenuous) and age 5-9,normal exercise and age 9-12,additional exercise (moderate) and age 9-12,additional exercise (strenuous) and age 9-12
D) Exercise,blocking variable - age
E) Normal exercise,additional exercise (moderate) ,additional exercise (strenuous)