What is the half-life of a pion in the reference frame of the patient undergoing pion therapy?

A. \(1.8 \times 10^{-10} \mathrm{~s}\)

B. \(1.8 \times 10^{-8} \mathrm{~s}\)

C. \(1.8 \times 10^{-7} \mathrm{~s}\)

D. \(1.8 \times 10^{-6} \mathrm{~s}\)