Stepping off the bus , a familiar face caught my attention . I was n't sure if he 'd remember me , but seconds later I figured . He did . It 's been two years now since we stayed in Weir House .
According to the above context, choose the best option to answer the following question.
Question: What may be the reason why they knew he recognized them ?
Options:
- He laughed .
 - He ignored them .
 - He smiled .
 - He pretended to be on the phone .


He smiled .