Of the following, which occurred first (chronologically)? Group of answer choices The Varna System emerged and its distinctions became more or less fixed.. Aryan Indo-European migration into the sub-continent of South Asia (India) Regional kingdoms began to replace most of the city-states of the northern region of Harappan Society The story of Purusha in the Rig-Veda was created and sung orally.

The first occurrence (chronologically) was

Regional kingdoms began to replace most of the city-states of the northern region of Harappan Society.

Explanation:

Of all that are stated in the question, Regional kingdoms began to replace most of the city-states of the northern region of Harappan Society first occured

Around 4,350 years ago, many factors responsible for migration led people to abandon their settlements and migrate to southern and eastern regions of India, according to a study by Indian Institute of Technology Kharagpur.

This is also known as Indus valley civilization

the correct answers are 1, 2 5, 6