Read the following context and choose the best option to answer the question.
Context: Eighteen minutes later , having driven an average speed of 80 mph , we 're back at our house to collect the tickets . Forty - five minutes later , we 're at the airport . Unfortunately , we 're three minutes late for the final check - in .
Question: Why were they late for check - in at the airport ?
Options: 
A. None of the above choices .
B. They had gotten lost trying to find their flight .
C. They had left their tickets at home on accident .
D. They were unable to leave at an earlier time .


C