Maria is studying the effects of calcium on the development of children. so she administers varying levels of calcium to two groups of children, one group consisting of children aged five and the other group consisting of children aged ten. she studies the growth rate of these two groups regularly over a period of one year. on the basis of the given evidence, it would be most accurate to say that maria is using research design.

Quasi-experimental research design

Explanation:

A quasi-experimental research design is similar to an experimental research design. It involves the manipulation of an independent variable but without the random assignation of participants to groups. Maria's experiment manipulates the administration of calcium, but the participants are not randomly assigned to the age groups, as they are already five or ten years old before the experiment and thus cannot be randomly assigned.

i think it is the third one.

b hope this