'Kahapana' in ancient India refers to:

Correct Answer: A type of coin (punch-marked)

Subject: history

A type of religious vow
A clan head
A type of coin (punch-marked)
A land grant

Explanation: Kahapana (Sanskrit: Karshapana) were punch-marked silver coins — the earliest standardized coins in ancient India, used extensively during the Mauryan period. They were irregular in shape but had a fixed weight (~3.4 grams). They are called 'punch-marked' because multiple symbols (sun, six-armed symbol, hills, animals, geometric shapes) were punched/stamped on them. They predate the Mauryan empire and are found in Mahajanapada-era sites. Important: the word 'Nishka' also refers to an early monetary unit/gold ornament used as currency in Rigvedic times.