I think is D , hope i answer fast enough haha :D
The z-score for 5 minutes is found from:


Reference to a normal distribution table shows that the cumulative probability for a z-score of 1.667 is around 0.9522.
Therefore the probability that a conversation lasts for longer than 5 minutes is:
1 - 0.9522 = 0.048 to 3 d.p.
I think that would be 0.202. ( Sorry if i'm wrong )
Hope helps?-aparri