Step 1: Understanding the structure of the sentence.
The verb required in the blank must fit grammatically and meaningfully in the phrase “to the finish line and back.” The sentence describes a simple action that involves running to a place and returning.
Step 2: Analyze the given options.
- (a) run away: Means to escape or flee, which does not fit the context of reaching a finish line.
- (b) run out of: Means to exhaust a supply (e.g., run out of time), incorrect here.
- (c) run: A simple base form verb meaning to move quickly on foot, fits perfectly with “to the finish line and back.”
- (d) run on: Means to continue for too long, grammatically incorrect for this context.
Step 3: Grammar rule.
The infinitive “to” is followed by the base form of the verb. Therefore, “to run” is grammatically correct.
Step 4: Conclusion.
The complete and correct sentence is: “I have to run to the finish line and back.”