What is meant by calling the Indus Civilization 'predominantly secular'?

It means that the political and social organization was not centered around religious institutions or clerical authority, unlike contemporary Mesopotamian ziggurats.

Secularism and Cotton in Indus Valley Civilization

Q: Regarding the Indus Valley Civilization, consider the following statements: 1. It was predominantly a secular civilization and the religious element, though present, did not dominate the scene. 2. During this period, cotton was used for manufacturing textiles in India. Which of the statements given above is/are correct?

Both statements are correct. The Indus Valley Civilization was predominantly secular in governance and was the first to use cotton for manufacturing textiles in India.

ID: HIS_ANC_2011_06 Ref: Upinder Singh, A History of Ancient and Early Medieval India

Regarding the Indus Valley Civilization, consider the following statements:
1. It was predominantly a secular civilization and the religious element, though present, did not dominate the scene.
2. During this period, cotton was used for manufacturing textiles in India.

Which of the statements given above is/are correct?