Which of the following is an opaque cloud in the lowermost layer of the atmosphere?
With reference to Clouds, consider the following statements: 1. Cirrus clouds are formed at low altitudes. 2. Stratus clouds are layered clouds. 3. Nimbus Clouds are extremely dense and opaque to rays of sun. 4. Cumulus clouds exist in patches and can be seen scattered. Which of the above statement(s) is/are correct?