The difference between the solutions is a concentration and volume change by 10%. Why does the difference in pH make sense for this difference

i think   the answer is c hope i'm right

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.