Answer: The phrase that best completes the sentence with parallel elements is "took a ferry ride".
Explanation: Parallel structure consists in repeating the same grammatical form within one sentence to show that all the ideas presented in that sentence are equally important. Moreover, parallel structures also contribute to make the reading easier. In the case of the sentence provided, the phrase that best completes it is "took a ferry ride" because the two previous verbs ("travelled" and "rode") have been conjugated into the Simple Past Tense. In that way, in order to add parallelism, "took a ferry ride", which contains a verb conjugated into the Simple Past Tense ("took"), should be part of the sentence. In contrast, the other options do not contain a verb conjugated into the Simple Past Tense; therefore, they cannot fill in the blank.