A civil engineer is designing a bridge over a river with fluctuating water levels. The bridge is expected to withstand various environmental conditions and loads over its lifespan. Which of the following factors should the engineer primarily consider during the design phase to ensure the structural integrity and durability of the bridge?

A$)$ The aesthetic appeal of the bridge design

B$)$ The cost$-$effectiveness of construction materials

C$)$ The impact of seismic activity on the bridge structure

D$)$ The availability of skilled labor for construction

E$)$ The compatibility of the bridge design with future technological advancements