Answer:
The correct answer is "b. Religions evolve over time." The fact that modern Buddhism is different from the early religion of the Indus Valley Civilization suggests that religions undergo changes and adaptations over time. This is a common phenomenon observed in many religions throughout history as they are influenced by cultural, social, and political factors. It is not necessarily an indication that the early religion was incorrect, but rather that it has evolved and adapted to new circumstances and contexts over time.