Final answer:
The altitude where 100% humidity is reached is called the b)lifting condensation level (LCL).
Step-by-step explanation:
The altitude where 100% humidity is reached is known as the b)lifting condensation level (LCL).
This is the height at which the relative humidity of an air parcel reaches 100% due to adiabatic cooling, and condensation begins, often visible as clouds. The dew point is the temperature at which air reaches this level of humidity. Understanding the LCL is crucial for predicting weather patterns, especially when assessing the potential for cloud formation, fog, or precipitation.