Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that parks can reduce local temperatures by up to 4 degrees Celsius during heatwaves. However, the effect depends on the size and tree coverage of the park. Small gardens with scattered trees only lower temperatures by 1 degree, while large, densely wooded areas have the most significant cooling impact. Interestingly, the study also showed that adding water features, like ponds, can extend the cooling effect to nearby streets, but only if the park is at least 2 hectares in size. So, city planners should prioritize larger, tree-rich parks over many small ones.
❓ According to the lecture, what condition makes a park's cooling effect extend to nearby streets?
A. A. The park must have a pond or water feature.
B. B. The park must be at least 2 hectares in size.
C. C. The park must have dense tree coverage and be large.
D. D. The park must be located in a heatwave-prone area.