Given below are two statements.
Statement-$I$ : Adiabatic work done is positive when work is done on the system and internal energy of the system increases.
Statement-$II$ : No work is done during free expansion of an ideal gas.
In the light of the above statements,choose the correct answer from the options given below.

• A
  Both statements-$I$ and Statement-$II$ are false
• B
  Statement-$I$ is true but statement-$II$ is false
• C
  Statement-$I$ is false but statement-$II$ is true
• D
  Both statements-$I$ and Statement-$II$ are true.