roth ira's differ from regular ira's in which of the following ways?

a. a contribution to a roth ira is nondeductible, whereas a contribution to a regular ira may be deductible or nondeductible

b. a spouse's active participation in an employer-provider retirement plan affects the ability to contribute toa roth ira but not to a traditional ira

c. an individual may contribute to borh a roth ira and toa traditional ira after reaching the age oo 701/2

d. distributions from a roth ira are always nontaxable whereas distributions from a regular ira are always taxable