I would say “What do you mean by that?”
This is one of my pet peeves. Parents should really teach children how to correctly identify their emotions at a young age so they can use the correct word choice as adults. The main categories like “love” and “angry” get misused in adulthood and cause misunderstandings. How much less awkward to say “I enjoy your company” or “I’m happy when I’m with you” or “I think you’re hot and want to sleep with you.” Likewise, “angry” is often a wide array of more precise word choices, ranging from irritated, put out, grouchy, tired and hungry to actually angry.
“Then you should say what you mean,” the March Hare went on.
“I do,” Alice hastily replied, “at least- at least I mean what I say- that’s the same thing, you know.”
“Not the same thing a bit!” said the Hatter. “You might just as well say that ‘I see what I eat’ is the same thing as ‘I eat what I see’!”