Which of the following is the best definition of an ordered-pair solution to a two-variable linear equation?

Which statement best explains why plotting a few ordered pairs and drawing a line through them represents infinitely many solutions to a linear equation?

Given the linear equation 3x + 2y = 12, find y when x = 2.

Given two points observed on a graph, $(2,-1)$ and $(5,8)$, derive the equation of the line in standard form $ax+by=c$ with integer coefficients.

Find x- and y-intercepts for the equation 5x + 2y = 20.