Final answer:
The RMS Titanic collided with an iceberg, and the correct answer is 'a) Iceberg; 409093'. The ship number rumor is an urban legend and unfounded.
Step-by-step explanation:
The RMS Titanic was an ocean liner that sank after it crashed into an iceberg in the North Atlantic Ocean. The correct answer to the fill-in-the-blank question is 'a) Iceberg; 409093,' although the assertion about the ship number reflecting to reveal an ominous message is purely urban legend with no factual basis.
The ship's manufacturer, White Star Line, did not have an anti-Catholic stance and these rumors are not supported by historical evidence. The Titanic tragedy was a result of a collision with an iceberg, not supernatural or conspiratorial causes.