What is IUPAC name of mesityl oxide?

What is IUPAC name of mesityl oxide?
  1. 4 $-Methylbenzaldehyde$
  2. 2 - Bromohexan-3-one
  3. 4 - Methylpent-3-en-2-one
  4. 1- Phenylbutan-2-one

Asked in: MHT CET 2020 (14 Oct Shift 1)

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