Answer:

Introduction:
The question asks about the reference of Videgha Mathava from the bank of Saravati to the bank of Sadanira. The correct answer is option 'A', which refers to the Aitareya Brahmana.

Aitareya Brahmana:
The Aitareya Brahmana is a Vedic text associated with the Rigveda. It is a prose text that contains explanations and rituals related to the hymns of the Rigveda. It is divided into eight books, and it is one of the earliest Brahmanas.

Videgha Mathava:
Videgha Mathava is a character mentioned in the Aitareya Brahmana. He was a king and a sage who performed a ritual journey from the bank of the river Saravati to the bank of the river Sadanira.

Significance of the Journey:
The journey of Videgha Mathava is significant because it symbolizes the transition from one stage of life to another. In Vedic culture, crossing a river represented crossing a threshold, both literally and metaphorically. It denoted a change in the status or role of an individual.

Symbolism:
The journey of Videgha Mathava from the bank of Saravati to the bank of Sadanira symbolizes the transition from the student stage to the householder stage in the Vedic education system. It represents the transition from a life of learning and discipline to a life of responsibilities and duties.

Explanation in Aitareya Brahmana:
The Aitareya Brahmana provides details of the journey of Videgha Mathava. It describes how he crossed the river Saravati and reached the other bank, where he performed certain rituals and sacrifices. He then continued his journey to the bank of the Sadanira river.

Conclusion:
In conclusion, the reference to Videgha Mathava's journey from the bank of Saravati to the bank of Sadanira is found in the Aitareya Brahmana. This journey holds significance in symbolizing the transition from the student stage to the householder stage in the Vedic education system.