Final answer:
True, a daily temperature curve exhibits a lag of about three hours relative to an insolation curve.
Step-by-step explanation:
The statement given in the question is true. A daily temperature curve exhibits a lag of about three hours relative to an insolation curve. This means that the peak temperature of the day occurs about three hours after the peak of sunlight or insolation. For example, if the peak insolation occurs at noon, the peak temperature will occur at around 3pm. This lag is due to various factors such as the time it takes for the Earth's surface to absorb and release heat.