At resonance, the LC parallel resonant circuit

For a parallel LC circuit, the admittance is given by $Y = \dfrac{1}{j \omega L} + j \omega C = j \left( \omega C - \dfrac{1}{\omega L} \right)$.

At resonance, the inductive reactance equals the capacitive reactance, which means $\omega C = \dfrac{1}{\omega L}$.

Substituting this into the admittance equation gives $Y = 0$.

Since impedance $Z = \dfrac{1}{Y}$, the impedance approaches infinity as the admittance approaches zero.

Therefore, at resonance, an LC parallel resonant circuit has a very high impedance.

Answer: has a very high impedance.