Researchers are developing low-cost devices. These devices can detect water pollutants in rivers and lakes.

A. Researchers are developing low-cost devices that can detect water pollutants in rivers and lakes.

B. Researchers are developing low-cost devices to detect water pollutants in rivers and lakes.

C. Researchers are developing low-cost devices so that they can detect water pollutants in rivers and lakes.

D. Researchers are developing low-cost devices who can detect water pollutants in rivers and lakes.