Step 1: Understanding the Concept
The volume is the scalar triple product \([\vec{a}-\vec{b}\ \ \vec{b}-\vec{c}\ \ \vec{c}-\vec{a}]\).
Step 2: Look for dependence
Adding the three vectors gives \((\vec{a}-\vec{b})+(\vec{b}-\vec{c})+(\vec{c}-\vec{a})=\vec{0}\).
Step 3: Conclude
So the vectors are linearly dependent, hence coplanar, and the triple product is 0.
Final Answer:
The volume is 0.
\[ \boxed{\text{(D) }0} \]