For Assertion: The acetals are unstable in the presence of aqueous solutions of acid because they undergo hydrolysis in the presence of acidic conditions to produce the parent aldehyde or ketone or alcohols. But are stable and do not undergo hydrolysis in the presence of a base or under neutral conditions.
Hence assertion is correct.
For reason: Alkoxide ion (RO–) is not considered a good leaving group
Hence reason must be false.
So, the correct option is A