Show me the steps to solve $14.$ Which of the following is a fringe benefit excluded from income?

a$.$ A mechanic at Denise$$s employer, a car rental company, provides $$1,000$ of repair services to Denise$$s personal car for free

b$.$ Alfa$-$Bet, a high$-$tech corporation, pays for each employee$$s membership at the $24$ Hour Biceps Gym closest to each Alfa$-$Bet office

c$.$ Quickchat Inc. gives each employee a $$10$ giftcard to the local coffee shop on National Coffee Day

d$.$ Hedaya, a doctoral student at Ivy University, receives a full tuition waiver while serving as research assistant