After a chemical spill in a nearby lake, residents began to notice a large number of dead turtles washing up on the shore.

What is the likely cause of the turtle deaths?
A) Overfishing of the turtles by the local fishermen.
B) Someone has introduced a new turtle predator to the lake's ecosystem.
C) The lake water mixed with the spilled chemical and created a toxic pollutant.
D) The elimination of the insects and plants that make up most of the turtle's diet.