Select the best answer from the choices below. What causes resonance? a. Destructive interference
b .Two nearby objects vibrating at the same frequency
c. A wave passing from one medium to another
d. Constructive interference

The match between the vibrations of the air column and one of the natural frequencies of the singing rod causes resonance. So ITS A  

Two nearby objects vibrating at the same frequency

Explanation:

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

wher is the rest of the question