Concept:Climate is the average weather condition of a place over a long period of time.
Explanation:Weather keeps changing daily, so a single season or year cannot describe the climate of a place.
A reliable climate record needs observations collected for a sufficiently long number of years.
Only after many years of data can we balance out unusual temperature, rainfall, and wind variations.
The period that is commonly accepted as long enough for this purpose is about 35 years.
During this time, both short-term changes and occasional extreme weather events are properly averaged.
Hence, the average atmospheric weather conditions for determining climate are taken over roughly 35 years.
Answer:B. 35 years