Read the following context and choose the best option to answer the question.
Context: I then went in to a computer and they had me put in my personal info . ( Name , address , past jobs , etc . ) After I finished that , I went to another section where I had to answer questions . They said something like , " My crack use affects my job " or " My meth use affects my job " , and you had to pick one answer , such as " Yes , it affects my job " to " I ' ve never used this illegal drug . "
Question: What may be the reason for them participating in the study ?
Options: 
- They had been offered pay to do it .
 - None of the above choices .
 - They enjoy doing research studies .
 - They wanted to help out the company .


They had been offered pay to do it .