Which of the following taxpayers must file a 2023 return?

a. Amy, age 19 and single, has \($8,050\) of wages, \($800\) of interest, and \($350\) of self employment income.

b. Betty, age 67 and single, has a taxable pension of \($9,100\) and Social Security benefits of \($6,200\) (the Social Security benefits are wholly tax-exempt in this situation).

c. Chris, age 15 and single, is a dependent of his parents. Chris has wages of \($3,800\) and interest of \($700\).

d. Dawn, age 15 and single, is a dependent of her parents. She has wages of \($425\) and interest of \($1,600\).

e. Doug, age 25, and his wife are separated. He earned \($5,000\) while attending school during the year.