Answer:
for the line to have a constant slope, the difference of every y- ordinate with the last ordinate has to be equal
to check this, we will use the following formula
y4 - y3 = y2 - y1
if both the LHS and the RHS are equal, the slope is constant and is irregular otherwise
5 - 8 = 7 - 3
-3 = 4
LHS ≠ RHS
Since LHS is not equal to RHS, the slope is NOT constant and hence keeps increasing or decreasing irregularly
Therefore, option 4 (Not a line) is correct