What is the **reciprocal** of $-\dfrac{3}{7}$?

The reciprocal of a fraction $\dfrac{a}{b}$ is $\dfrac{b}{a}$. The reciprocal preserves the sign. Reciprocal of $-\dfrac{3}{7}$ is $-\dfrac{7}{3}$. Check: $\left(-\dfrac{3}{7}\right) \cdot \left(-\dfrac{7}{3}\right) = +1$ ✓. - Trap B drops the negative sign (incorrect — the product of a number and its reciprocal must equal $+1$, which requires same sign). - Trap C inverts to positive without flipping. - Trap D is just the original.