They are adjectives that describe fun events.
The answer to your question would be that the statement that describes best sentence 2 is the the one that says that the example is a compound sentence. That is the correct option is the last one.
A compound sentence joins two or more independent clauses with a coordinator such as for, and, or but, or a semicolon.
1) The right-handed twin always did the right thing, (clause 1)
2) and the left-handed twin always did everything backward. (clause 2)
