बंगाल के किस पुरातात्विक स्थल से 'पंचचूड़ा' (पाँच केशपिनों वाली यक्षिणी) को दर्शाने वाली प्रसिद्ध मृण्मूर्तियाँ (टेराकोटा) प्राप्त हुई हैं?

In Ancient Indian Statecraft, Kautilya's 'Rajamandala' theory primarily deals with:

The First Buddhist Council was held at ______.

Which ancient Indian text contains references indicating that population counts or census-like records were maintained in ancient India?