An arrow is drawn horizontally to the left to represent a displacement along the x-axis, where the positive x-direction is to the right. Which algebraic sign should accompany the numerical value of this displacement?
a) A negative sign (−) because the arrow points opposite to the positive x-direction.
b) A positive sign (+) because any displacement is a distance moved.
c) No sign; only the magnitude is needed for displacement.
d) Either a + or − sign; the sign is irrelevant as long as the magnitude is correct.