When bicyclists are riding with others, what is the rule regarding riding side-by-side?

• Bicyclists can ride as many side-by-side as they want
• Bicyclists must ride in a single-file line if they are impeding traffic
• Bicyclists must not ride more than two side-by-side unless it is a path or part of a roadway reserved for bicycles only
• Both B & C
  Explanation:

  "If bicyclists are riding with others, they may not ride more than two side-by-side unless it is a path or part of a roadway reserved for bicycles. They must ride single file if they and the other rider are impeding traffic."