Jim contracted with United Technologies to install 5,000 feet of Rocketfish Cat-5e network cable in his new office building. United installed 5,000 feet of Dynex Cat-5e network cable instead. The types of cable are essentially the same. When Jim sued for breach of contract, the court likely found that United's actions constituted:
a. complete performance.
b. material breach.
c. substantial performance.
d. incomplete performance.