To be honest , he had such a strong german , japanese accent when he spoke English I had to focus when he spoke ! ! I found out he lived in Germany for 4 years . I was fascinated with his history and his experiences ! Right , the MOST memorable part of the night was .... we stole our wine glasses and we went out the bar , by the river ... he bent over to sit down ... and his phone dropped into the river ! ! !
According to the above context, choose the best option to answer the following question.
Question: Why may his phone have fallen into the river ?
Options:
- She knocked it in when he sat down .
 - He was tired of talking and dropped it in .
 - He dropped it in by accident .
 - It was too close to the river and slipped in .


He dropped it in by accident .