Question about hyperventilation

If a person is hyperventilating, the blood has:

A) increased saturation of hemoglobin with O2.

B) a higher level of CO2.

C) a higher pH level.

D) an increase in carbonic acid.

Every time I look back at old notes it all says that hyperventilation causes an high pp. CO2 and thus increase in [H+] which means lower pH. I choose B, but the answer is C. C is completely contradictory to my notes so I thought I'd ask you guys to help explain why it's right! HELP

Question about hyperventilation