A 2.50kg mass connected to the end of an ideal spring oscillates in simple harmonic motion. The mass's position is described as a function of time by x(t)=0.20cos(8.00t+0.50) where all quantities are in base SI units. Which one of the following choices gives the numerical value of the oscillation's amplitude in base SI units?
(A) 8.00 (B) 4.00 (C) 1.60 (D) 0.50 (E) 0.20