Answer:
(b) Plan III
Step-by-step explanation:
You want to know which of plans I through IV do not result in pieces that will make a triangular frame.
Each of the plans results in three pieces of molding that have a total length of 24 inches. In order for them to form a triangular picture frame, their lengths must satisfy the triangle inequality: the sum of the two shorter lengths must exceed the longest length.
8 + 8 = 16 > 8. This plan is possible.
7 + 7 = 14 > 10. This plan is possible.
4 +8 = 12 is not greater than 12. This plan is not possible.
6 + 8 = 14 > 10. This plan is possible.
The complete list of plans that are not possible is {Plan III}, choice B.