Comparing between cleavage of ethers

We have to find out which ether would undergo cleavage faster.[![](https://i.stack.imgur.com/j0Y8Y.jpg)](https://i.stack.imgur.com/j0Y8Y.jpg)


**My Attempt**


IV. I couldn't figure out, so i carried out simple SN1 cleavage. Since +M effect of OH > OCH3 1st reactant seemed right answer. But I am wrong. Why and what would be process?


V. I believe since there are no 3° Carbon, so process of cleavage should be SN2. The answer comes out right, but is my analysis right?


Please help.




[![enter image description here](https://i.stack.imgur.com/DTyfG.jpg)](https://i.stack.imgur.com/DTyfG.jpg)


**I found this answer for IV**


**And in V-B is formed because it is more conjugated** 


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