Answer:
Most likely if I had to choose I would pick C
Explanation:
A : Its not letter A because it dosent mention the time or place at all
B : It states the time but not the place
C : Its says the place "Summer Palace" and there going around lunch time
D : It states the time "20 days" but there not very specific about the "land"
It was a tough call between C and D but I would pick C.
