His name is "Jehovah" just as much as it's "I Am." They're both interpretations the Hebrew text.
It's weird that you'd say that it can't be "Jehovah" because "God spoke Hebrew" and then present an English phrase as the correct answer.
And again if some guys name is Jose you not going to call him Joseph. You don't call Jesus Joshua even though thats his name in english. So you can't pronounce a name with a J if there is no J.
"Jehovah" is still just as correct as "I am."