Question

A paper airplane used to study wing designs is an example of a ?

Answer 1

Option A, many mental illnesses are used to define an individual, is the right answer.  

A disease is a critical unusual condition that adversely influences the structure or performance of a part or full of a person or animals, and that is not due to any outside harm. Therefore, patients suffering from these conditions are called medical disease that can be cured by using medicines. Whereas, mental illness is a behavioral or imaginative exemplar that creates notable suffering or impairment of bodily functions. Thus, the main difference between labeling a person with medical illness and mental illness is that many mental disorders are employed to describe an individual,

Answer 2

Model I'm guessing. Coz that's using an object to explain