Which tax form is used by the following individuals? 
a. Anita is single, age 68, and has a salary of $22,000 and interest of $300.
b. Betty owns an apartment complex that produced rental income of $36,000. Expenses totaled $38,500.
c. Clay’s wife died last year. He qualifies as a surviving spouse. His salary is $24,000.
d. Donna is a head of household. Her salary is $27,000 and she has $200 of interest income.