Kamrup is an ancient name of which of the following state of India?

Kamrup or Kamarupa is the modern region situated between two rivers Manas and Barnadi in Western Assam, congruent to ancient "Kamapitha", "Kamarupa Mandala" of Pragjyotisha Bhukti, medieval "Sarkar Kamrup" and modern "Undivided Kamrup district", though historian Dinesh Chandra Sircar suspects Kamapitha division as fabrications from late medieval times.