5) What caused Jacques Cousteau to use a one-man submarine to explore the Great Blue Hole?
A)
There is a large number of bacteria in The Great Blue
Hole.
B)
The center of The Great Blue Hole is nearly 500 feet
deep.
C)
There are sharks at the bottom of The Great Blue
Hole.
D) Scuba Divers needed a route to follow.

Jacques Cousteau made the Great Blue Hole famous in 1971 when he declared it to be one of the world's best diving sites. A part of the Belize Barrier Reef Reserve System and a UNESCO World Heritage Site, the Hole exists within the Lighthouse Reef approximately 40 miles offshore. Cousteau's grandson Fabien recently returned to the Hole with Sir Richard Branson and a team of explorers to capture many high-quality photos and videos of the Hole's enigmatic characteristics via a three-person Aquatica Submarine (the Stingray 500), a Roatan Institute of Deepsea Exploration Submarine (the Idabel), and sonar technology provided by Kongsberg Mesotoech. The expedition, with Aquatica's Chief Pilot and Oceanographer, Erika Bergman at the helm, was broadcast live on the Discovery Channel on December 2, 2018.

Explanation:

"it's more of an essay than story, but perhaps it is best described as a mood-piece: it uses a lot of musical imagery, not to mention sea imagery, religious imagery, and any other imagery that suits his purpose."