The roads of New Orleans remained flooded due to the hurricane.

Which type of relationship is used in the sentence?

Not a compound sentence, no.

"Which" indicates you've been given choices. What are they? And what do YOU think?

The type of relationship used in the sentence is a cause and effect relationship. The hurricane is the cause, and the flooded roads are the effect.

The type of relationship used in the sentence is a cause and effect relationship.

I would believe its a compound sentence.