The correct answer is ran.

Step-by-step Explanation:

1. Analyze the Sentence Structure:
The given sentence is: "He _________ a long distance". Here, "He" is a singular subject. We need a simple past tense main verb to complete the predicate logically in the past tense.

2. Evaluate the Options:

• running: This is a present participle (v-ing form). It requires an auxiliary verb (such as was or is) before it to form a complete verb phrase (e.g., "He was running"). Without a helping verb, it is grammatically incorrect here.

• runned: The verb "run" is an irregular verb. Its past tense form is "ran", not "runned". Therefore, "runned" is not a valid word in standard English grammar.

• ran: This is the simple past tense form of the irregular verb "run". It correctly follows the subject "He" to indicate a completed action in the past (e.g., "He ran a long distance").

• run: This is either the base form or the past participle form. For the simple present tense with a third-person singular subject ("He"), the verb would need to be "runs" (e.g., "He runs"). Thus, "run" alone is incorrect in this context.

Conclusion:
The simple past form ran appropriately fills the blank to make the sentence grammatically sound.