Answer: Option (A)
Step-by-step explanation:
Thermal stress is also known as insolation and it is a physical weathering process in which the rocks becomes weak and and shatters due to the fluctuating temperature condition. It is a common type of weathering process. For example, a rock getting heated up in the day time and at night it cools again, thereby breaking the rocks apart.
Thus, the correct answer is option (A).