In the context of civil engineering, what primary function does palm oil shell serve in lightweight concrete?

A$)$ Palm oil shell acts as a substitute for conventional cement, enhancing the durability of lightweight concrete structures.

B$)$ Palm oil shell contributes to the reduction of construction costs by minimizing the need for additional reinforcement in lightweight concrete.

C$)$ Palm oil shell aids in achieving the desired lightweight properties of concrete, crucial for applications where weight reduction is imperative in civil engineering projects.

D$)$ Palm oil shell is primarily utilized in civil engineering to increase the thermal conductivity of lightweight concrete constructions