Final answer:
The statement that abyssal plains are more extensive on the floor of the Atlantic compared to the Pacific is true, due in part to the slower sea-floor spreading at the mid-Atlantic Ridge and less tectonic activity creating flatter regions known as abyssal plains.
Step-by-step explanation:
The statement that abyssal plains are more extensive on the floor of the Atlantic as compared to those on the floor of the Pacific is true. One of the reasons for this is the presence of the mid-Atlantic Ridge, which is a continuous mountain range that runs north-south through the Atlantic Ocean and is a site where new ocean floor is created due to separating tectonic plates, specifically Europe and North America moving apart. As the ocean floor spreads, it creates flat areas known as abyssal plains in the process. Abyssal plains are usually found at depths greater than 4,000 meters and are among the flattest, smoothest regions on Earth. They are more extensive in the Atlantic Ocean because the sea-floor spreading rate is slower than in the Pacific, where faster spreading rates and much more frequent tectonic activity lead to more irregular topography with less extensive abyssal plains. Further, the Pacific being home to many deep ocean trenches contributes to a less uniform and expansive abyssal plain.