Douglas covered a distance of 2 miles while swimming across Lake Wentworth.

- **Understanding the Question:** The question asks for the distance that Douglas covered while swimming across Lake Wentworth.
- **Key Information:** The key information provided in the question is the name of the lake, "Wentworth," and the available options for the distance covered: a) 4 miles, b) 3 miles, c) 5 miles, and d) 2 miles.
- **Analyzing the Options:** To determine the correct distance, we need to evaluate each option based on the given information.
- **Option a) 4 miles:** This option suggests that Douglas covered a distance of 4 miles. However, the correct answer is given as option d) 2 miles. Therefore, option a) can be eliminated.
- **Option b) 3 miles:** This option suggests that Douglas covered a distance of 3 miles. However, the correct answer is given as option d) 2 miles. Therefore, option b) can be eliminated.
- **Option c) 5 miles:** This option suggests that Douglas covered a distance of 5 miles. However, the correct answer is given as option d) 2 miles. Therefore, option c) can be eliminated.
- **Option d) 2 miles:** This option suggests that Douglas covered a distance of 2 miles. As the correct answer is indeed 2 miles, we can conclude that option d) is the correct answer.
- **Explanation:** Based on the provided information and the elimination of incorrect options, we can determine that Douglas covered a distance of 2 miles while swimming across Lake Wentworth.
- **Summary:** Douglas covered a distance of 2 miles while swimming across Lake Wentworth.