Here are the best answers for the sentences:

5. **C. The more clearly - the better**
"The more clearly they communicate, the better they get to know each other."

6. **A. The more money - the more smart**
"The more money she saves, the more smart she can invest." (Note: "the wiser" is more commonly used instead of "the more smart.")

7. **A. The more confident - the more comfortable**
"The more confident she becomes, the more comfortable she feels in her own skin."

8. **C. The more curious - the wider**
"The more curious they are about things, the wider their knowledge can become."

If you need any more help or clarification, feel free to ask!