How long has their son probably been doing drugs?

Choices:
A. not enough information
B. Seven years
C. Two years
D. For a few weeks
For a few weeks
"Maybe we're being too harsh with the letter," said Janine.
"Hon, as his parents we have a responsibility to his well being," said Bob.
"I know but I just think he doesn't need this added pressure."
"Jan, I'll be damned if I'm gonna support and house a drug addict."
"I just think maybe he's going through tough times or something. He told me the other day he wanted to see a therapist."
"Hmm."
"Maybe there's something going on we don't understand. I mean didn't he seem a little paranoid to you today at lunch?"
"Paranoia is a side-effect of the marijuana."
"Well I still think we are being a little harsh, I mean, we can't just throw our son out on the street."
"Babe, its our job to be harsh when it comes to this kind of stuff. It's for his own good. Either he chooses to keep living rent free in the condo without the pot or he chooses to ruin his life."
"I know but don't you think we should let this little phase run its course? I mean, we're not entirely innocent ourselves. Eventually he's gonna want to stop smoking pot,"
"I don't know if he is, Jan. He's expressed to me several times that he has no interest in quitting."
"He's said that to me too."
"Well I think that's a pretty big red flag, don't you?"
"Yes."
"He needs to get his priorities in order and realize that drugs aren't gonna do him any good. If we have to force him to do that then that's what has to be done. I mean, tell me you haven't had any difficulty falling asleep at night with the notion that our sons are drug addicts."
"Well at least Ben has a job and is paying his own rent."
"I know but those people he hangs out with, Mack and Allison, those dopers that spend their time smoking weed, they...they're our age, and did you see their house, the stacks of books and newspapers and the marijuana pipes laying on the coffee table? It sickens me that there are people out there like that."