听力原文：MB I just wanted to remind you that registration for little league baseball's already started, and if you want the kids to take part, you need to register them before the end of the month. Are you planning on enrolling them this year？
WB Yes, but... registration's already begun？ It's only January! When does the league begin？
MB The league doesn't start until May, but... yes, we always do registration this early. And let me tell you, with all the kids that sign up, and all the games that need to be scheduled, we need to do this early, so we can focus on getting kids ready to play once the league begins.
WB Wow, I don't remember it being this early last year. Yes, of course... I'll drop by and register the kids this week. Is it going to cost the same as last year, or has it gone up？
Why has the man contacted the woman？

A. To schedule an appointment
B. To invite her children to an event
C. To inform. her of a change in policy
D. To remind her of an important deadline