Final answer:
The magnitude of the resultant vector cannot be determined without additional information.
Step-by-step explanation:
The magnitude of the resultant vector can be found using the Pythagorean theorem. Since the question does not provide any additional information or context, it is not possible to determine the correct answer from the given options alone. To find the magnitude of a resultant vector, you need the magnitudes and directions of the individual vectors being added. Without that information, we cannot calculate the magnitude of the resultant vector.