The correct answer is: a) Kaveri, Vaigai, Palar.
The Kaveri is the longest river in Tamil Nadu. It originates in the Western Ghats in Karnataka and flows through the states of Karnataka, Tamil Nadu, and Puducherry. The Vaigai is a river in the state of Tamil Nadu. It originates in the Western Ghats and flows through the districts of Madurai, Theni, Dindigul, and Sivagangai. The Palar is a river in the state of Tamil Nadu. It originates in the Western Ghats and flows through the districts of Vellore, Tiruvannamalai, and Krishnagiri.
The other options are incorrect because they do not include any rivers that flow through Tamil Nadu. The Krishna, Godavari, and Narmada are rivers that flow through the states of Andhra Pradesh, Telangana, Maharashtra, Madhya Pradesh, and Gujarat. The Ganga, Brahmaputra, and Mahanadi are rivers that flow through the states of Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, West Bengal, Assam, and Odisha. The Sutlej, Beas, and Ravi are rivers that flow through the states of Himachal Pradesh, Punjab, and Haryana.