Which ordered pair (x, y) makes this relation a function?

{(2,3), (–2,5), (4,4), (-4,5), (x, y)}

A. (-4, -1)
B. (-1,-1)
C. (-2,-1)
D. (2, -1)

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Adecibel is a logarithmic unit that can be used to measure the intensity of a sound. the function y = 10logx gives the intensity of a sound in decibels, where x is the ratio of the intensity of the sound to a reference intensity. the reference intensity is generally set at the threshold of hearing. use the graphing utility to graph the decibel function. a whisper has a sound intensity of 30 decibels. use your graph to you complete the following statement. the sound intensity of a whisper is times the reference intensity.

Solve for x: 5/3 x = 20/21 it's fraction. remember to simplify your fraction