Were there any other Choices but to use the atomic bomb in World War 2?

Yes and we were committed to carrying out all of them, but the atomic bomb was used first and Japan surrendered so none of the other choices were needed, thus saving many millions of lives on both sides and ending the war at least a year sooner than anyone expected.

• a Japanese D-Day invasion landing
• chemical weapons attacks on Japan
• continued 1000 plane firebombing raids
• etc.