Answer:
D. Comma splice
Explanation:
A <em>comma splice</em> happens when you join two independent clauses with a comma and no conjunction. Here we have two independent clauses
Tammy is an effective leader.
She leads by example.
They are joined with a comma without any conjunction. It is an error called <em>comma splice.</em>
Cats were praised for killing venomous snakes and protecting the Pharaoh since at least the First Dynasty of Egypt.
That in the medium you are trying to make the middle of the story sound different.<span />