Read the source given below and answer the question that follows.

The Peninsular Plateau is flanked by stretches of narrow coastal strips, running along the Arabian Sea in the west and the Bay of Bengal in the east. The western coast, sandwiched between the Western Ghats and the Arabian Sea, is a narrow plain. It consists of three sections. The northern part of the coast is called the Konkan (Mumbai - Goa), the central stretch is called the Kannad Plain, while the southern stretch is referred to as the Malabar Coast. The plains along the Bay of Bengal are wide and level. In the northern part, it is referred to as the Northern Circar, while the southern part is known as the Coromandel Coast. Large rivers, such as the Mahanadi, the Godavari, the Krishna and the Kaveri have formed extensive deltas on this coast. Lake Chilika is an important feature along the eastern coast.

Which four rivers form the extensive delta in this coast?