Historically, Chinese architects have used what to create mortar for buildings?

C.

For centuries, Chinese architects mixed sticky rice with lime mortar to create buildings, bridges, and city walls. Rice would first be cooked into a sticky paste, then blended with sand and lime, creating what was often referred to as “Chinese concrete.” The use of sticky rice, which is naturally water resistant, boosted the structures’ strength and protected the buildings against erosion. According to Atlas Obscura, rice was often used in construction in China by the time of the Tang Dynasty (816-907 AD).