To find the equivalent expression when x=0, we substitute 0 for x in the given expression and simplify it.
-12x³8x = -12(0)³8(0) = 0
Therefore, we are looking for an expression that equals 0 when x=0.
Option A: 3x²+2 = 3(0)²+2 = 2, which is not equal to 0.
Option B: -8x² - 4x = -8(0)² - 4(0) = 0, so this could be the correct answer.
Option C: -16x² - 12 = -16(0)² - 12 = -12, which is not equal to 0.
Option D: 8x²+4 = 8(0)²+4 = 4, which is not equal to 0.
Therefore, the answer is B, -8x² - 4x.