Mr$.$ and Mrs$.$ Smith are both under $65,$ but Mrs$.$ Smith is retired on permanent and total disability. Regarding the credit for the elderly or the disabled, what is the AGI limit for a married filing jointly couple $($both under age $65)$ with one qualifying spouse?

Select one:

a$.$ $$17,500$

b$.$ $$20,000$

c$.$ $$12,500$

d$.$ $$25,000$