Final answer:
Using the formula for the speed of deep water waves with the given ocean depth of 764 meters, the calculated speed of a tsunami would be approximately 86.5 m/s. However, this exact value does not match any of the given multiple choice options, suggesting a need to recheck the question or options.
Step-by-step explanation:
To find the speed of a tsunami in a region of the ocean that is 764 meters deep, we can use the formula for the speed of deep water waves, which is √(g × d), where g is the acceleration due to gravity (9.81 m/s2) and d is the depth of the ocean. Performing the calculation, we have:
Speed = √(9.81 m/s2 × 764 m) = √(7482.84 m2/s2) ≈ 86.5 m/s
This value is not exactly given in any of the options A to D, so we must look at the problem or given options again to make sure no additional information or different units of measure are provided.