(A) to be in hot water → means to be in trouble or a difficult situation → matches with (IV)
(B) to gild the lily → means to add unnecessary decoration to something already beautiful, i.e., to over-embellish → matches with (III)
(C) to fly off the handle → means to suddenly lose one's temper or become angry unexpectedly → matches with (I)
(D) to sweep something under the rug → means to hide or conceal a problem rather than addressing it → matches with (II)
Hence, Option 2: (A) - (IV), (B) - (III), (C) - (I), (D) - (II) → This correctly matches all four idioms with their precise meanings, demonstrating accurate understanding of these common English expressions → correct