Assuming that an AGI limitation does not apply, what amounts of credit for the elderly or the disabled would be permitted in each of the following instances? Allowable Credit a. b A single taxpayer eligible for the credit who receives $2,000 of nontaxable social security benefits. Taxpayers filing a joint return for which one taxpayer is eligible for the credit and the taxpayers have received no social security benefits. Taxpayers filing a joint return, and both are eligible for the credit and received $4,000 of nontaxable social security benefits. C