Answer:
The adverb phrase in road races modifies the word competes.
Step-by-step explanation:
Adverb phrases are phrases (a group of words that is missing a subject) that modify, describe or gives further information of adjectives, verbs or other adverbs. They tend to provide information that answer the following questions: "Why?", "How?", "When?", "Where?" or "In what circumstances?".
In the sentence, in road races is the adverb phrase because it provides information about the place where Simone competes; therefore, it modifies the verb compete: Where does Simone frequently compete? Answer: In road races.