Can someone check my sentences to see if they need change or no change when it falls under the rule of Predication:

Question

1.Our resolutions should begin at midnight on January 1.

2. The reason for the cat's illness is because she was allergic to the dog.

3.A book that has an exciting introduction and a surprising ending would be the best story for me to read.

4.The driving exam is when one is tested on the rules of the road.

5. The Homeowners' Association rules were created to ensure that the neighborhood looked nice.

1.Our resolutions should begin at midnight on January 1.
correct
2. The reason for the cat's illness is because she was allergic to the dog.
There is both an "is" and "was" in this sentence. The tense needs to agree.
3.A book that has an exciting introduction and a surprising ending would be the best story for me to read.
correct
4.The driving exam is when one is tested on the rules of the road.
this is a little awkward... I would say "the driving exam includes tests on the rules of the road."
5. The Homeowners' Association rules were created to ensure that the neighborhood looked nice.
correct

is this sentence correct

The reason for the cat’s illness is she is allergic to the dog.

A book that has an exciting introduction and a surprising ending would be the best story for me to read