What is this math please help ASAP

Answer:
A) A line
Step-by-step explanation:
Notice that:
x-y=4
-y=4-x
y=-4+x
y=x-4
The equation y=mx+b produces a line, so A) a line would be correct
Answer: is a line
Step-by-step explanation:
because does it have to be a line from a line