Larry is a military retiree who receives social security benefits. Although he lives in Pennsylvania, he spends more than half his time in Maryland due to his consulting jobs. He is 66 years old. Which of the following is a true statement

a.) The states that levy an income tax will always confirm to federal tax law

b.) Social Security benefits are always exempt from state taxes.

c.) In some cases, a taxpayer may have to file resident tax returns in two states because he is a dual resident

d.) military retirement pay is always exempt from state taxes