Let \( r \) and \( \theta \) respectively be the modulus and amplitude of the complex number \( z = 2 - i\!\left( 2 \tan \dfrac{5\pi}{8} \right) \), then \( (r,\theta) \) is equal to:
\( \left( 2 \sec \dfrac{3\pi}{8}, \dfrac{5\pi}{8} \right) \)
\( \left( 2 \sec \dfrac{5\pi}{8}, \dfrac{3\pi}{8} \right) \)
\( \left( 2 \sec \dfrac{3\pi}{8}, \dfrac{3\pi}{8} \right) \)
\( \left( 2 \sec \dfrac{11\pi}{8}, \dfrac{11\pi}{8} \right) \)