Assertion : An electron is not deflected on passing through certain region of space. This observation confirms that there is no magnetic field in that region. Reason : The deflection of electron depends on angle between velocity of electron and direction of magnetic field.

• 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.