Which expression is equivalent to 8 x 3 + 8 - x 3 - 2 ?

Choice B is correct. The given expression is equivalent to $8x^3+8-x^3-\left(-2\right)$, or  $8x^3+8-x^3+2$. Combining like terms in this expression yields $7x^3+10$.

Choice A is incorrect. This expression is equivalent to $\left(8x^3+8\right)-2$, not $\left(8x^3+8\right)-\left(x^3-2\right)$.

Choice C is incorrect. This expression is equivalent to $\left(8x^3+8\right)-\left(-2\right)$, not $\left(8x^3+8\right)-\left(x^3-2\right)$.

Choice D is incorrect. This expression is equivalent to $\left(8x^3+8\right)-\left(x^3+2\right)$, not $\left(8x^3+8\right)-\left(x^3-2\right)$.