If the osmotic pressure of a solution at $300 \ K$ is $0.0821 \ atm$,what will be the concentration of the solution in $mol/L$?

• A
  $0.033 \ M$
• B
  $0.066 \ M$
• C
  $0.33 \times 10^{-2} \ M$
• D
  $3 \ M$