To find the slope of the arithmetic sequence, we need to determine the common difference between the consecutive terms.
On day one, they baked 5 muffins.
On day two, they baked 11 muffins.
On day three, they baked 17 muffins.
Now, let's find the differences:
From day one to day two:
11 - 5 = 6
From day two to day three:
17 - 11 = 6
The common difference (or slope) of this arithmetic sequence is 6.
So, the correct response is 6.