The correct option is Kalibangan and Lothal.
Explanation
The presence of fire altars in the Indus Valley Civilization serves as archaeological evidence for ritualistic fire worship. This practice highlights regional variations in religious beliefs within the civilization, distinct from the Mother Goddess worship prevalent in other major cities.
Site-Specific Analysis:
- Kalibangan (Rajasthan): A series of seven fire altars were discovered on the citadel mound. These altars were arranged in a row, often associated with wells and bathing platforms, suggesting they were used for public or community rituals.
- Lothal (Gujarat): Fire altars have also been excavated at this site, indicating that fire worship was a common practice in the Gujarat region of the Harappan civilization.
- Harappa and Mohenjodaro: These sites are characterized by the Great Bath and numerous terracotta figurines of the Mother Goddess. They do not show significant evidence of fire altars, suggesting a difference in religious focus compared to Kalibangan and Lothal.
Key Takeaway: Fire altars are a distinctive feature of Kalibangan and Lothal, signifying the practice of fire cults or ritual sacrifices in the Rajasthan and Gujarat regions of the Indus Valley Civilization.