Answer:
A. Permutation; number of ways = 720
Step-by-step explanation:
For the first medal, we have 6 runners that can earn it.
For the second medal, we have 5 runners because there's one who won the first one.
For the third, we have 4 runners.
And so on up to the 6th medal where we have just one runner left.
As this happens all at the same time, we have to multiply them.
Ways to award the medals = 6*5*4*3*2*1 = 6! = 720
Remember that a permutation is a combination where the order matters. So, in this case, is a permutation because each medal is different.