Which of the following statements is/are incorrect?

a. The surrounding landscape of Vijayanagara is characterised by stunning granite hills that seem to form a girdle around the city. b. Embankments were built along the streams that flow down the river from these rocky outcrops, to create reservoirs of varying sizes. c. The Kamalapuram canal, built by the Sangama dynasty, drew water from a dam across the Tungabhadra and irrigated the cultivated valley of Vijayanagara.