Consider the following climatic and geographical phenomena: 1. Condensation 2. High temperature and humidity 3. Orography 4. Vertical wind Thunder Cloud development is due to which of these phenomena?

1. Thunder cloud (Cumulonimbus) development requires specific atmospheric conditions. 2. Essential ingredients include moisture (humidity) which, upon cooling, undergoes condensation (Statement 1) to form cloud droplets. 3. Instability, often driven by surface heating leading to high temperature (Statement 2), causes air parcels to rise. 4. A lifting mechanism is needed to initiate the upward movement of air. This can be convection (related to Statement 2), orography (air forced up mountains - Statement 3), or weather fronts. 5. Strong vertical wind (updrafts - Statement 4) is characteristic within a developing thundercloud, sustaining its growth, but the initial trigger usually involves factors like condensation, temperature/humidity, and a lifting mechanism like orography. However, the most fundamental processes initiating cloud formation involve moisture and cooling/lifting. 6. Considering the options, the combination of Condensation (1) and High temperature and humidity (2) provides the basic conditions (moisture and instability trigger) for the initial development leading to thunder clouds, although orography and vertical wind are also involved in the full process. Option A (1 and 2) focuses on the fundamental requirements for cloud formation and initial instability.