Final answer:
In Indus Valley cities, the monumental ceremonial center was likely the citadel, serving important practical and possibly ceremonial functions, aligning with the civilization's practical approach to urban planning and daily life. (Option C).
Step-by-step explanation:
The question refers to what may have served as the monumental ceremonial center in Indus Valley cities.
The correct answer is c. a citadel. Indus Valley civilizations did not construct massive monuments for gods or golden tombs for leaders.
Their practical approach to life is exemplified by structures like the Great Bath of Mohenjo-Daro, a public bathing area indicating advanced urban planning and sewage systems. They were more focused on utility and daily life functions rather than monumental architecture.
The citadel, being a central and fortified area within the cities, is thought to have played a key ceremonial role in these societies. (Option C).