Donna made a picture frame as a gift for her mom. To make it more stable, she wants to add a brace to the back of it running diagonally from one corner to the other. About how long does that brace need to be? A) 41 in
B) 82 in
C) 4.5 in
D) 29 in

I think C is the correct answer

first option

a function is a relation in which an input is paired with exactly one output.

so, let's find the right answer.

in our first option, our inputs are january, february, and march. the outputs are 30, 28, and 25. each input has it's own output. this is correct!

our second option we know is incorrect, because ms. valverade has two outputs, dogs and cats. this is not a function.

our third option is incorrect as well. the yellow square has two ouputs, the square and the triangle.

lastly, in our fourth option, we see the number 7 two times with a different output. therefore, this is not a function.

remember: each input must be paired with only one output!