When the water containing air becomes saturated, it means that the air has reached its maximum capacity to hold water vapor. This saturation occurs when the air is unable to evaporate any more water molecules, leading to the formation of clouds and eventually precipitation. The correct answer to this question is option 'D' - clouds will be formed. Let's explore this in more detail.

Cloud Formation:
When water vapor in the air condenses into tiny water droplets or ice crystals, clouds are formed. This process occurs when the air becomes saturated with water vapor. As warm air rises, it expands and cools, causing the water vapor to condense and form visible water droplets or ice crystals. These droplets or crystals cluster together to create clouds.

Factors Affecting Cloud Formation:
Several factors can contribute to cloud formation:

1. Humidity: When the air contains a high amount of water vapor, it has a higher capacity for holding moisture. As the air becomes saturated, clouds begin to form.

2. Temperature: As air rises and cools, its ability to hold water vapor decreases. When the air reaches its dew point temperature (the temperature at which it becomes saturated), clouds form.

3. Atmospheric Stability: Stable atmospheric conditions can inhibit cloud formation. However, when the air becomes unstable due to temperature variations or the presence of a front, it creates conditions favorable for cloud formation.

Types of Clouds:
Clouds can vary in shape, altitude, and appearance. The most common cloud types include:

1. Cumulus Clouds: These clouds are fluffy, white, and have a flat base. They often indicate fair weather conditions.

2. Stratus Clouds: These clouds form in layers and appear as gray sheets covering the sky. They are often associated with overcast or foggy conditions.

3. Cirrus Clouds: These high-altitude clouds are thin and wispy, appearing like feathers or mare's tails. They often indicate fair weather but can precede a change in weather patterns.

Conclusion:
When the air becomes saturated with water vapor, clouds begin to form. This occurs when the air reaches its maximum capacity to hold moisture, leading to the condensation of water droplets or ice crystals. Clouds play a crucial role in the Earth's weather patterns and can indicate impending precipitation or changes in atmospheric conditions.