Arrange the following Director Generals of the Archaeological Survey of India in chronological order:

A) John Marshall
B) Alexander Cunningham
C) R.E.M. Wheeler

B-A-C

The discovery of Harappa preceded that of Mohenjodaro, but unfortunately, Harappa suffered significant damage due to extensive brick theft. As early as 1875, Alexander Cunningham, the inaugural Director-General of the Archaeological Survey of India (ASI) and revered as the father of Indian archaeology, documented that the amount of brick taken from the ancient site would have been sufficient to construct a railway line stretching approximately 100 miles between Lahore and Multan. Consequently, numerous ancient structures at Harappa were adversely affected. In contrast, Mohenjodaro fared much better and experienced superior preservation.
John Marshall's appointment as Director-General of the ASI brought about a significant shift in Indian archaeology. As the first professional archaeologist to work in India, Marshall leveraged his experience from excavations in Greece and Crete.
R.E.M. Wheeler, who became Director-General of the ASI in 1944, recognized the need to follow the stratigraphy of the mound instead of uniform horizontal lines. He brought military precision to the practice of archaeology, rectifying the shortcomings of Marshall's approach.