Why is the speaker calling? A. To offer some advice B. To extend an invitation C. To ask for assistance D. To make a reservation

Câu hỏi :

Question 1 - 3 refer to following conversation:

Hi, Yu-mi. This is Chris. I'm supposed to give an important presentation today, but there's a problem, and I need your help. (72) The flight I was supposed to take has been pushed back by two hours due to the heavy snowstorms. I'm going to try to find a train to take me to our headquarters in Chicago, but I doubt I'll make it in time for the meeting. (71) Would you mind filling in for me at the presentation this morning? You're the only other person who fully understands the marketing strategy proposal I'm supposed to present. (73) I have all the files and presentation slides here on my laptop, so I'm going to send these to you right away. Please check your e-mail, and call me back if you have any questions. Thank you so much. 

1. Why is the speaker calling?