A．At four.B．At half past four.C．After five o’clock.D．At……

Ma Lili’s parents are going to give a birthday party for her. She’s going to be fourteen years old. Ma Lili has a lot of friends. They are going to come to the party. They are girls from Ma Lili’ s school. There are twenty-five of them.
Ma Lili’s mother is making birthday cakes for the party. They are very nice cakes. Ma Lili says to her mother:" Mum, you’re very nice. Thank you for your nice cakes. " Her father is going shopping. He buys a lot of apples, bananas, oranges and pears.
It’s four o’clock in the afternoon. Now everything is ready. The party begins in thirty minutes.
What time does the party begin ( )

A．At four.
B．At half past four.
C．After five o’clock.
D．At about six o’clock.