Which of the following conformations will be the most stable?

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :

Assertion A : Acetal / Ketal is stable in basic medium.

Reason R : The high leaving tendency of alkoxide ion gives the stability to acetal/ketal in basic medium.

In the light of the above statements, choose the correct answer from the options given below :

The correct order in aqueous medium of basic strength in case of methyl substituted amines is :

Match the List-I with List-II :

Correct match is -