IRAC Method need !

Carol carried on a consulting business as a sole proprietorship. She met Steven Stevenson at a conference. Steven told Carol that he was a "senior litigator and parenter" in a mid-sized Saskatoon law firm and gave her a business card that set out his name and the name "Stevenson, Smith, Jones, and Khan, Barristers and Solicitors." Steven asked Carol to do some work for the firm, Carol did the work and sent a bill for $20,000 to Steven. While providing the services, Carol recieved letters from Steven on paper bearing, at the top, the same firm name as the business card and the full names of Stevenson, Smith, Jones, and Khan at the bottom. Steven did not pay. Carol sued Steven along with Smith, Jones, and Khan. Assuming that Steven and the three others individuals named on the letterhead were not partners, will Carol succeed in holding them liable for her account? What else would you need to know to answer the question?