The overall average temperature and precipitation of a particular region a. weather b. climate

Climate. The weather changes on a day to day basis, climate is an average based on the weather.

Weather means the state of the temperature, precipitation, etc. at a given moment in time.
Climate is the average state of the temperature, precipitation, etc. of an area over a long period of time.
Example:
If a place that is normally hot and dry gets rain one day and becomes quite humid, then the weather that day is rainy and humid, while the climate (basically average weather) is hot and dry.

So the answer is B. climate.