Crossword Genius

I have no idea what could ultim­ately make son upset (4,3,2)

Ross

I believe the answer is:

dont ask me

I'm a little stuck... Click here to teach me more about this clue!

'i have no idea' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'what could ultimately make son upset' is the wordplay.
'ultimately' indicates one should take the final letters.
'upset' indicates an anagram.
The final letters of 'what could' are 'td'.
'td'+'make'+'son'='tdmakeson'
'tdmakeson' anagrammed gives 'DONT ASK ME'.

Can you help me to learn more?

I've seen this clue in The Guardian.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.