A particle in SHM is described by the displacement equation \[x(t)=A\cos (\omega t+\theta ).\]If the initial (t = 0) position of the particle is 1 cm and its initial velocity is \[\pi \]cm/s, what is its amplitude? The angular frequency of the particle is \[\pi {{s}^{-1}}\] [DPMT 2004]

• A. 1 cm
• B. \[\sqrt{2}\]cm
• C. 2 cm
• D. 2.5 cm