Final answer:
The expression that represents the length, in inches, of one row of Molly's quilt is (s+3).
Step-by-step explanation:
The expression that represents the length, in inches, of one row of Molly's quilt is (s+3).
In the problem, it is stated that the side lengths of each square on her new quilt are 3 inches longer than the side lengths of the squares on her previous quilt. So, to find the length of one row of Molly's quilt, we add 3 inches to the side length s of the squares on the previous quilt.
Hence, the correct answer is d) s+3.