Final answer:
Yokohama is the port in Tokyo Bay that was destroyed in the Great Kanto earthquake of 1923 and later by US bombing during WWII.
Step-by-step explanation:
The port in Tokyo Bay that was destroyed in 1923 by the Great Kanto earthquake, and again by US bombing in WWII is A) Yokohama.
The Great Kanto earthquake had a magnitude of 7.8 on the Richter scale and resulted in catastrophic damage to Yokohama as well as Tokyo. Nearly 150,000 people perished due to the earthquake and its consequent disasters, which included fires and tsunamis.
During WWII, Yokohama also faced significant destruction due to US bombing raids, given its status as an important industrial center and a part of the urbanized region that would eventually support Japan's growing manufacturing sector post-war.