Final answer:
The driest part of the state is the desert region (C), which is characterized by very little rainfall and significant temperature differences between day and night.
Step-by-step explanation:
The driest part of the state is likely to be the desert region. Deserts are characterized by receiving extremely low amounts of precipitation throughout the year. This is due to various factors, such as the rain shadow effect, where moist air rises over mountain ranges, loses moisture, and causes the leeward side to be much drier. In the desert region, evaporation of moisture is significant due to the hot and sunny climate. Type B climates, such as deserts, typically have very little rainfall and significant temperature variations between day and night. Considering these factors, the correct answer to the question is C. Desert region.