Step 1: Understanding the Concept
The vector projection of \(\bar{a}\) on \(\bar{b}\) is \(\bar{c}=\frac{\bar{a}\cdot \bar{b}}{|\bar{b}|^{2}}\bar{b}\), a scalar multiple of \(\bar{b}\).
Step 2: Compute a . b
\(\bar{a}\cdot \bar{b}=2-4+2=0\), so \(\bar{c}=\bar{0}\).
Step 3: Evaluate the triple product
A scalar triple product with a zero vector, or with two parallel vectors, is 0.
Final Answer:
The triple product is 0.
\[ \boxed{\text{(B) }0} \]