In which one among the following texts does the term kshetra-patni ('mistress of the field') originate?

1. A

   Rigveda

   Rigveda is the earliest Vedic text consisting of hymns dedicated to various deities, but it does not contain the specific term kshetra-patni, making this option incorrect.

2. B

   Atharvaveda

   Atharvaveda. This text contains hymns and charms reflecting domestic and social life, and the term kshetra-patni ('mistress of the field') originates here in the context of agricultural fertility and land ownership rituals.

3. C

   Ashtadhyayi

   Ashtadhyayi is Panini's foundational treatise on Sanskrit grammar and linguistics composed during the later classical period, not the Vedic source where this agrarian term originates.

4. D

   Arthashastra

   Arthashastra is Kautilya's ancient Indian treatise on statecraft, economic policy, and military strategy, which deals extensively with state administration and revenue rather than the Vedic textual origin of this term.

Summary. Official key is (b) because the term kshetra-patni ('mistress of the field') has its textual origin in the Atharvaveda, while the other foundational texts belong to different literary or administrative traditions.