Verbs in Past Tense:
The verb in past tense in the given sentence is "stood".

Explanation:
To identify the verb in past tense, we need to understand the concept of verb tenses. Verbs indicate actions, occurrences, or states of being. They can be classified into different tenses to show when the action or state occurred.

In the given sentence, "Joe stood watching him," we can identify the verb in past tense by following these steps:

1. Identify the subject: The subject of the sentence is "Joe."

2. Identify the verb: The verb in the sentence is "stood."

3. Determine the tense: To determine the tense of the verb, we need to analyze the form of the verb. In this case, "stood" is the past tense form of the verb "stand."

4. Confirm the tense: The verb "stood" is indeed in the past tense as it refers to an action that occurred in the past. It indicates that Joe was in a standing position while watching him.

5. Eliminate other options: The other options provided, such as "watching," "Joe," and "him," are not verbs in past tense. "Watching" is a present participle, "Joe" is the subject, and "him" is the object.

Therefore, the correct answer is option 'A' - "Stood."

By identifying the verb in past tense, we can understand the timeframe of the action or state being described in the sentence. In this case, the past tense verb "stood" indicates that Joe was standing at a specific time in the past while watching someone.