Ron is single and has reached full retirement age. He is working and earning $$55,000$ per year. Are his social security benefits taxable, and if so$,$ what percent of his benefits are taxable?

A$.$ Yes, up to $50\%$ of his social security benefits are taxable.

B$.$ No$,$ his social security benefits are not taxable

C$.$ Yes, all his social security benefits are taxable.

D$.$ Yes, up to $85\%$ of his social security benefits are taxable.