Consider the following statements about a cloud form: 1. These are made up of ice crystals rather than droplets of water. 2. They are thin, stringy, white clouds that trail like feathers across the sky. 3. These clouds are formed at very high altitudes — normally between 6000 metres and 10000 metres. Which one among the following cloud forms is described above? **[CAPF (ACs) 2026]**