Final answer:
The width of the yard must be less than 35 ft based on the given information.
Step-by-step explanation:
The perimeter of a rectangle is calculated by adding the lengths of all its sides. In this case, since we know one side is 50 ft, we need to find the remaining side. Let's assume the width of the yard is w ft. The perimeter is less than 170 ft, so we can set up the inequality:
2(50 + w) < 170
Simplifying the inequality, we have:
100 + 2w < 170
2w < 70
w < 35
Therefore, the width of the yard must be less than 35 ft. None of the given options match, so we cannot determine the specific width of the yard based on the information provided.