question_answer

Assertion             :       \[_{Z}{{X}^{A}}\] undergoes \[2\alpha -\]decays. \[2\beta -\] decays and \[2\gamma -\]decays and the daughter product is \[_{Z-2}{{Y}^{A-8}}\]. Reason                 :       In a-decay the mass number decreases by 4 and atomic number decreases by 2. In b- decay the mass number remains unchanged, but atomic number increases by 1 only.  [AIIMS 2001]

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.