$\text{ax+by=c}$
Here if we put $\text{a=kd, b=ke, c=kf}$
we get $\text{dx+ey=f}$
which is same as $\text{2nd}$ equation
So, thiese two are same line putting condition I
Now, By condition II putting $\text{a=b=1, d=e=2}$
we get two lines are parallel
So, Answer$: \text{(D)}$ if the question cannot be answered even by using both the statements together.