The PH of a Sample of Water from a River

Multiple Choice

The pH of a sample of water from a river is 6.0.A sample of effluent from a food processing plant has a pH of 4.0.The concentration of hydronium ion in the effluent is

A) one and a half times (1.5x) larger than the river hydronium ion concentration.
B) two times (2x) larger than the river hydronium ion concentration.
C) four times (4x) larger than the river hydronium ion concentration.
D) 100 times (100x) larger than the river hydronium ion concentration.