This sentence has unequal ideas joined by a subordination conjunction.
Since the ideas in the sentence imply causation (the broken pulleys caused the inability to raise the flag) it means that the ideas are unequal. It is also necessary to join them with a subordinating conjunction, which show the causality within the sentence. In this case that subordination conjunction is "because".
I would say the answer is C but I’m not totally sure sorry
Answer:
Group of answer choices During interval training, you're alternating between bursts of intense speed and periods of recovery.
and
As you change speed during your run, you're heart rate will be constantly rising and falling.
