Which is the completely factored form of 12x3 – 60x2 + 4x – 20?

Factor out 4 to get 4(3x³ − 15x² + x − 5). Group the terms: 4[3x²(x − 5) + 1(x − 5)] = 4(3x² + 1)(x − 5), which is choice D.

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