´We must substitute each pair into our equation:
A. If we substitute poin (45,3), we have

that is, this point doesnt belong to the line.
B. If we substitute poin (3,45), we have

then, this point doesnt belong to the line.
C. If we substitute poin (0,30), we have

then, this point is a solution.
D. If we substitute poin (30,0), we have

then, this point doesnt belong to the line.
Therefore, the answer is option C