Step 1: Understanding the Question:
• The question asks in which museum the earliest standing Buddha statue dedicated by Bhikshu Bala in the Kushan period is kept.
Step 2: Detailed Explanation:
• The standing Bodhisattva (Buddha) image dedicated by Bhikshu Bala, dated to the Kushan period, was found at Sarnath and is kept in the Archaeological Museum, Sarnath.
• The Madras Museum, Indian Museum (Calcutta) and the Museum of Archaeology, Mathura hold other sculptures and are not the repository of this image.
Step 3: Final Answer:
The correct option is (D) Archaeological Museum, Sarnath.