In the following passage some words have been deleted. Fill in the blanks with the help of the alternatives given. Select the most appropriate option for each blank.
The Great Stupa at Sanchi is one of the oldest stone structures in India. It was originally commissioned (1)______ Emperor Ashoka in the 3rd century BCE. Its nucleus (2)______ a simple hemispherical brick structure built (3)______ the relics of the Buddha. It was crowned by the chhatri, a parasol-like (4)______ symbolising high rank, which was (5)______ to honour and shelter the relics.
Select the most appropriate option to fill in blank No.4.