The irrigation device called ‘Araghatta’ was

(a) a water bag made of leather pulled over a pulley
(b) a large wheel with earthen pots tied to the outer ends of its spokes
(c) a larger earthen pot driven by bullocks
(d) a large water bucket pulled up by rope directly by hand

The correct answer is (b) a large wheel with earthen pots tied to the outer ends of its spokes.

Explanation

The Araghatta (also known as the noria or sometimes confused with the “Persian wheel”) was a mechanical water-lifting device used for irrigation in ancient and medieval India.

Its mechanism consisted of a large wheel, often turned by animal power (like bullocks or camels) or sometimes by water current. A series of earthen pots were attached to the rim of this wheel. As the wheel rotated, the pots at the bottom dipped into the water source (like a well or river), filled up, were carried to the top, and then tipped their water into a trough that fed the irrigation channels.

(a) a water bag made of leather… This describes a different device, commonly known as the mhot or charas.
(c) and (d) are incorrect descriptions of the mechanism.