To determine whether a point lies on a certain line, you need to know the equation of that line. There are a number of ways you could find the equation of a line. For instance, if you are given two points, you can determine the slope and then the equation. Also, if you are given the slope and one point, you can deduce the equation of a line.

Statements (1) and (2) are both insufficient on their own: each gives you one point. (1) tells you that (0,4) is on the line, while (2) tells you that (4,0) is on the line. Neither is enough to generate the equation of the line.

Taken together, the statements are sufficient. With two points (whether they are intercepts or not), you can find the slope and then determine the equation of the line. Once you have the equation of the line, you can figure out whether (6,-2) is on the line. Choice (C) is correct.