Read the following context and choose the best option to answer the question.
Context: made snap judgments about fellow conference - goers which may or may not have been appropriate or well - founded . wished we 'd been able to get into the control tower.went back to room and read . travel partner went to meet with advisor to work on presentation . fell asleep just before opening session ; was woken by travel partner 30 min later .
Question: What was the reason that he was late to the meeting ?
Options: 
- He overslept .
 - The meeting with the advisor ran late .
 - None of the above choices .
 - They could n't get into the control tower .


He overslept .