Answer:
Option D, x = 4
Step-by-step explanation:
Option A: y = 4 doesn't work because that line would be horizontal
Option B: y = 4x doesn't work because that would be diagnol
Option C: x = -4 doesn't work because that would a vertical line at -4
Option D: x = 4 works because that would a vertical line at 4
Answer: Option D, x = 4
