根据下列短文,回答下列各题。 During the SUmmer session there will be a revised schedule of services for the universitycommunity.Specific changes for intercampus bus services,the cafeteria,and summer hours forthe infirmary(医务室)and recreational and athletic facilities will be posted on the bulletin 60 ard outside of the cafeteria.Weekly movie and concert schedules which are in the process ofbeing arranged will be posted each Wednesday outside of the cafeteria.Intercampus buses will leave the main hall every hour on the half hour and make all of theregular stoDs on their route around the campus.The cafeteria will serve breakfast,lunch,andearly dinner from 7 a.m.to 7 P.m.during the week and from noon to 7 P.m.on weekends.Thelibrary will maintain regular hours during the week,but shorter hours on Saturdays and Sun—days.The weekend hours are from noon t0 7 P.m..AU students who want to use the library borrowing services and the recreational,athletic,and entertainment facilities must have valid summer identification cards.This announcementwill also appear in the next issue of the student newspaper. Which of the following is the main purpose of this announcement?
A.
To tell campus personnel of the new library services.
B.
To announce the new movies on campus this summer.
C.
To notify university people of important schedule changes.
D.
To remind students to validate(使生效)their identification cards.