Question

what action broke off us negotiations with japan?
○ japans war with china
○ japans invasion of indochina
○ japans pact with germany and italy
○ japans pact with indochina

Explanation:

In 1941, Japan's move to occupy southern Indochina (a full invasion/expansion of its presence there) led the U.S. to cut off oil exports and break off diplomatic negotiations, as it was seen as a major aggressive escalation threatening U.S. interests in the Pacific. Japan's war with China had been ongoing without immediately breaking negotiations, the Axis pact was earlier and did not end talks, and a pact with Indochina did not exist.

Answer:

Japan's invasion of Indochina