Multiply.(x4 + 1)(3x2 + 9x + 2)

Distribute each term in x⁴ + 1 across 3x² + 9x + 2. Multiplying by x⁴ gives 3x⁶ + 9x⁵ + 2x⁴, and multiplying by 1 gives 3x² + 9x + 2. Adding these terms matches choice B.

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