Dependent, because it cannot be a sentence on its own.
D. We collected shells because we wanted to use them to make a necklace.
Answer: Tool #1: The Power of Scene.
Tool #2: The Power of Experience.
Tool #3: The Power of Sensory Detail.
Tool #4: The Power of Voice.
Tool #5: The Power of Conflict.
Explanation:
I believe that the answer is “ they aren’t sufficiently brief” because the irony is that he’s expected to make brief summaries so since they aren’t brief then that’s irony.