Which of the following statements is true regarding the taxation of Social Security benefits?

a.85% is the maximum amount of taxable Social Security benefits.

b.50% is the maximum amount of taxable Social Security benefits.

c.If a taxpayers only source of income is $10,000 of Social Security benefits, then 50% of the benefits are taxable.

d.If a taxpayers only source of income is $10,000 of Social Security benefits, then 85% of the benefits are taxable.