1. **Problem:** A selection in which the order of choice is important is known as? 2. **Explanation:** When order matters in selection, the concept used is called a permutation. 3. **Formula:** Permutations count the number of ways to arrange $r$ objects out of $n$ distinct objects, given by $$nP_r = \frac{n!}{(n-r)!}$$ 4. **Important rule:** Combinations are selections where order does not matter, permutations are where order matters. 5. **Answer:** The correct term is **Permutation**. **Final answer:** (c) Permutation