The maximum velocity of a body vibrating with a simple harmonic motion of amplitude 150 mm and frequency 2 vibrations/sec, is A. 188.5 m/sec B. 18.85 m/sec C. 1.885 m/sec D. 0.18845 m/sec

The correct answer is $\boxed{\text{C}}$.

The maximum velocity of a body vibrating with a simple harmonic motion of amplitude $A$ and frequency $f$ is given by:

$$v_{max} = \omega A$$

where $\omega = 2\pi f$ is the angular frequency.

In this case, we have $A = 150 \text{ mm} = 0.15 \text{ m}$ and $f = 2 \text{ vibrations/sec} = 2 \pi \text{ rad/sec}$. Substituting these values into the equation for $v_{max}$, we get:

$$v_{max} = 2\pi (2 \pi) (0.15 \text{ m}) = 1.885 \text{ m/sec}$$

Option A is incorrect because it is too large. Option B is incorrect because it is too small. Option D is incorrect because it is much too small.