Step 1: Context.
The passage clearly identifies Mr. William as the person responsible for burning leaves.
Step 2: Option Analysis.
(A) Mr. William: Correct — Explicit in the text.
(B) Ms. Greene: Incorrect.
(C) Mr. Johnson: Incorrect.
(D) Mrs. Smith: Incorrect.
Step 3: Conclusion.
The correct answer is (A) Mr. William.