Read the following context and choose the best option to answer the question.
Context: I ' m going to take a nap now . Also , just on a random aside , Buena Vista Social Club was like , the most boring documentary ever . The only cool thing was the street scenes of Cuba , and the interviews with Ibrahim Ferrer .
Question: What may be the reason for them taking a nap ?
Options: 
- They are sick .
 - They 're tired .
 - They slept too much the night before .
 - They are depressed .


They 're tired .