Answer:
To find the median, we need to first arrange the number of days exercised in ascending order:
0, 1, 1, 2, 3, 4, 5, 6, 7
There are 9 numbers in total, so the median is the middle number. Since there are an odd number of numbers, there is only one middle number. The middle number is 3, so the answer is:
c) 4