With reference to the Indian History, Alexander Rea, A.H. Longhurst, Robert Sewell, James Burgess and Walter Elliot were associated with

Explanation

In 1854, Walter Elliot, the commissioner of Guntur (Andhra Pradesh), visited Amaravati and collected several sculpture panels and took them away to Madras. (These came to be called the Elliot marbles after him.) He also discovered the remains of the western gateway and came to the conclusion that the structure at Amaravati was one of the largest and most magnificent Buddhist stupas ever built – says NCERT. Hence, A is the answer