Which of the following best defines a function? a] a function is a special type of relation for which there is a rule that pairs each input with exactly one output. b]a function is a relationship that defines the connection between two variables. c] a function is a set of ordered pairs in which no y-value repeats. d]a function pairs input and output values with no particular pattern.

 A. A function is a special type of relation for which there is a rule that pairs each input with exactly one output.

Option B is incorrect because it does not include that there cannot be two x-values with the same y-value. Option C is incorrect because it is a relation, not just a set of ordered pairs. Option D is incorrect because there is a particular pattern in a function.

Hope this helps!