I came across this question recently:
Now, they all are secondary alcohols so their dehydration should follow E1 mechanism and the stability of the carbocation formed in the RDS should be considered while comparing their rates.
Following this rule, I think, the answer should be (B) as ketone group shows (-)R effect in (C) and (-)I effect in (A) and (B), all which destabilize the carbocation formed.
But the actual answer is (A). How can that be? Is there some other mechanism to follow? I can’t understand what am I doing wrong.