Scientists developed a new margarine containing plant ingredients they think will lower blood cholesterol levels in people who use the margarine. they want to test this by comparing the cholesterol levels of people who use the new margarine for a while to cholesterol levels of a group of people who use regular margarine. this is an example of what type of research design?

Intervention study

Explanation:

The goal of Intervention studies is to measure the efficacy of a particular treatment or preventive measure by allocating individual subjects to one or more prevention and treatment options.

In applied psychology, the interventions are actions carry out to bring change in people. these interventions are not directed towards treating a problem or condition but are directed to foster healthy attitudes, emotions, and habits. These can improve the quality of living even in the absence of mental illness.

answer; the correct answer is (ethics);

intimacy, passion and commitment are the components of a interpersonal relationship emphasized in the triangular theory of love by robert sternberg.

the triangular theory of love says love can be comprehend as this componest form the vertices of a triangle.  

intimacy relates to feelings such as of closeness and connection;

passion relates the drives that brings people together, as physical attraction.

commitment relates to the being in a long-term relationship.