Explanation:

- Hiranya: Typically referred to a tax or tribute paid in cash, often linked to land revenue. It wasn't specifically related to a plough tax.

- Sulka: This generally refers to a toll or duty, especially related to trade and commerce. It wasn't a tax directly related to agriculture.

- Halivakara: This was a specific tax (plough tax) imposed by the Gupta rulers on every cultivator owning a plough. It was linked to agricultural productivity and land cultivation.

- Kara: This term generally represents a generic tax or duty. It wasn't specifically a plough tax during the Gupta rule.