Step 1: Concept
The absolute value $|x-3|$ is always $\ge 0$.
Step 2: Analysis
For $f(x) = 10 - |x-3|$ to be maximum, the term $|x-3|$ must be at its minimum value.
Step 3: Conclusion
The minimum value of $|x-3|$ is 0, which occurs when $x-3=0 \implies x=3$.
Final Answer: (B)