1. **State the problem:** Find the value of $p(0)$ for the polynomial $p(x) = 3x^2 + 6x - 1$. 2. **Formula and explanation:** To find $p(0)$, substitute $x=0$ into the polynomial. 3. **Substitute and simplify:** $$p(0) = 3(0)^2 + 6(0) - 1 = 0 + 0 - 1 = -1$$ 4. **Answer:** The value of $p(0)$ is $-1$. Hence, the correct choice is d. -1.