$1.$One conclusion of the RAND Health Insurance Experiment was that

a$.$ people are more price sensitive when it comes to outpatient visits than when it comes to inpatient visits.

b$.$ on average, the more people pay for their health care, the more inpatient and outpatient visits they make.

c$.$ people are not price sensitive when it comes to health care.

d$.$ the demand curve for health care is vertical $($perfectly inelastic$).$