Step 1: Find the slope of line \(AB\).
\[
m_{AB}
=\frac{3-(-3)}{6-4}
=\frac{6}{2}
=3
\]
Step 2: Find the slope of the required line.
Since the required line is perpendicular to \(AB\),
\[
m=-\frac{1}{3}
\]
Step 3: Equation through the origin.
Using point-slope form,
\[
y=-\frac13x
\]
Multiplying by \(3\),
\[
x+3y=0
\]
Step 4: Final conclusion.
\[
\boxed{x+3y=0}
\]
Hence, the correct option is \(\boxed{(A)}\).