Select the most appropriate option that can substitute the underlined segment in the given sentence.
Gulliver hear his watch ticking in his pocket.

The correct answer is could hear his watch ticking.

Step-by-step Explanation:

1. Analyze the Original Sentence:
The given sentence is: "Gulliver hear his watch ticking in his pocket."

2. Identify the Grammatical Error:
The subject "Gulliver" is a singular noun in the third person. In the present tense, it requires the singular verb "hears", not "hear". Furthermore, the context refers to a past event from Jonathan Swift's story Gulliver's Travels, so a past tense modal or verb structure is appropriate.

3. Evaluate the Options:
• could hear his watch ticked: Incorrect. The modal "could hear" is followed by an object ("his watch"), which requires a present participle ("ticking") or bare infinitive ("tick") to describe an ongoing action being perceived, not a past participle ("ticked").
• watch ticking: Incorrect. Omitting the verb leaves the sentence without a main predicate verb.
• could hear his watch ticking: Correct. "Could hear" properly conveys past ability/perception, followed by the object "his watch" and the continuous participle "ticking" to denote the continuous sound of the watch mechanism.
• heard his watch tickling: Incorrect. "Tickling" means light touching that causes laughter or twitching, which does not make sense for a watch mechanism (the correct sound term is "ticking").

4. Conclusion:
Substituting the underlined segment with "could hear his watch ticking" makes the sentence grammatically correct and meaningful: "Gulliver could hear his watch ticking in his pocket."