The world's largest known aquiferGroup of answer choicesPecos Valley AquiferEdwards-Trinity AquiferOgallala AquiferGulf Coast Aquifer

The largest known aquifer in the world is the Ogallala Aquifer. This vast underground water source spans several states in the United States, including Texas, New Mexico, Oklahoma, Colorado, Kansas, Nebraska, and Wyoming. It is primarily composed of porous materials that allow for the storage and flow of groundwater.

The Ogallala Aquifer plays a crucial role in supporting agricultural activities in the region, providing irrigation water for crops, which is vital in areas with limited rainfall. Its extensive size and supply are significant to many communities and the agricultural economy, though it is essential to manage this resource wisely due to concerns about declining water levels and sustainability.

In conclusion, among the options provided, the Ogallala Aquifer stands out as the largest known aquifer globally.