Assertion : Electromeric effect is brought into play only at the requirement of the reagent. Reason : It is a temporary effect in which bond pair is shifted to one of the constituent atoms.

• Correct answer
  A

  If both assertion and reason are true and reason is the correct explanation of assertion
• B

  If both assertion and reason are true but reason is not the correct explanation of assertion
• C

  If assertion is true but reason is false
• D

  If both assertion and reason are false.

Solution

It is a temporary effect. It comes into play instantaneously at the demand of the attacking reagent and as soon as the attacking reagent is removed the original condition is restored.
This effect is applicable on a multiple bond.

Hence, the correct answer is option: 'A'.