An idiom/phrase is given in bold. Following this idiom/phrase are given three sentences, which use the given idiom/phrase. The idiom/phrase may or may not be used correctly in one or more sentences. Identify the sentence(s) that use(s) the idioms/phrases incorrectly either in grammar or context and mark the answer accordingly.
Cut corners
I. The builder cut corners by using low-quality materials, leading to a weak structure.
II. She cut corners in the race and won unfairly.
III. The chef cut corners by skipping essential ingredients, ruining the dish.
Which sentence(s) use(s) the idiom incorrectly?