Assertion : If different gases are filled turn by turn at the same pressure in the discharge tube the discharge in them takes place at the same potential. Reason : The discharge depends only on the pressure of discharge tube and not on the ionisation potential of gas.

• A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
• C. If assertion is true but reason is false.
• D. If the assertion and reason both are false.
• E. If assertion is false but reason is true.