The draft entities listed below are for a pet store that sells not only food, treats and toys but animals as well. Below is a current draft of DOG, CAT, BIRD, RODENT. In attempting to optimize your design you decide that you need to make some improvements to your model. What suggestion do you have for this model?

$\backslash$table$[[$RODENT$],[\backslash$table$[[$RodentID: VARCHAR $[$PK$]],[$Breed: VARCHAR$],[$DOB: VARCHAR$],[$Color: VARCHAR$],[$LifeSpan: VARCHAR$]]]]$

The design is fine. No improvements need to be made.

Create a sub entity called ANIMAL with super types for DOG, CAT, RODENT and BIRD.

Create one entity called DOG$\_$CAT to reduce the number of entities by one.

Place all common attributes in a super type called ANIMAL and create sub types for all the different animals.