28. Mr. Walker plans to buy tickets for a play. He says: Mr. Walker: There is a play at 7 pm on Friday. How about watching it together?

Mrs. Walker: Sure, that would be great.

Olivia : I'm busy but I can't say no.

Oliver : It sounds good but I have to attend an online course. :

Owen : Yeah, why not?

According to the conversation above, how many tickets is Mr. Walker going to buy?

A) 5
B) 4
C) 3
D) 2​