The resonant angular frequency \( \omega_0 \) of an LCR circuit is given by the formula:
\[
\omega_0 = \frac{1}{\sqrt{LC}}
\]
Substitute the given values:
- \( L = 1 \, \mu H = 10^{-6} \, H \),
- \( C = 1 \, \mu F = 10^{-6} \, F \).
Thus:
\[
\omega_0 = \frac{1}{\sqrt{(10^{-6})(10^{-6})}} = \frac{1}{\sqrt{10^{-12}}} = 10^6 \, {rad/s}
\]
Hence, the correct answer is (A).