Option (C) is correct because the provided text explicitly identifies the Yamuna as a polluted river. Table 9.2 details the 'Sources of Pollution in the Ganga and the Yamuna Rivers,' listing specific polluted stretches like Delhi to the confluence with Chambal. Furthermore, the caption for Figure 9.1 refers to the 'heavily polluted Yamuna on the outskirts of New Delhi.' The other rivers (Brahmaputra, Satluj, and Godavari) are not mentioned in the context provided.