In which of the following ways do PPOs differ from HMOs?

Select one:

a$.$ HMOs provide benefits on a prepaid basis.

b$.$ PPOs focus on preventive measures and outpatient care.

c$.$ PPOs aim at providing high quality health services at high costs.

d$.$ HMOs contract with employers rather than employees.

e$.$ Physicians are paid on a flat salary basis in PPOs.