The correct options are
C As the Cauvery enters Tamil Nadu, it flows on the Stanley Reservoir and later flow on to form the Hogenakkal waterfalls.
D The Cauvery first meets its tributaries Noyyal and Amravati at Thirumukkudal and further meets one of its major tributaries called Bhavani.
The Cauvery originates at Talacauvery in the Brahmagiri hills in Karnataka. The river also acts as a border between Tamil Nadu and Karnataka. As the Cauvery enters Tamil Nadu, it forms the Hogenakkal waterfalls and later flows on the Stanley Reservoir. The Cauvery first meets one of its significant tributaries named Bhavani and further meets one of its major tributaries called Noyyal and Amravati at Thirumukkudal. The Cauvery has a wider flow and is known as Agandra Cauvery.