Please help me out of taxation homework for Q.3,8&9. Thank you so much!

A Z and X are the divorcedparents of JR. The divorce was granted in June of 1991 and Z was given custody, except for specific visits to X. Z provided $3,500 and X provided $4,000 toward JR's total support of $7.900. Which one of the following is true for the current year? entitled to the dependency exemption, becauseX provided more than 50 percent of JR's support b. If Z signs an agreement waiving the dependency exemption and it is attached to X's return, X may take the dependency exemption. c. If no agreement is signed, Z is entitled to the dependency exemption. d. Both b and c