Here we want to find the possibles magnitudes of the sum of two vectors.
Sadly, the options are not given, so I will give you the range of all the possible magnitudes of the sum of these two vectors.
We will find that any magnitude in the range: 58cm ≤ M ≤ 100cm is a possible magnitude or the resultant vector.
How we can find that range?
What we need to do is find the maximum and minimum.
The minimum is the case where the two displacements are in opposite directions, in that case, the magnitude of the sum will be:
79cm - 21cm = 58cm
The maximum is when both displacements are in the same direction, thus we must add the displacements, then we have:
79cm + 21cm = 100cm
Thus, any magnitude in the range:
58cm ≤ M ≤ 100cm
Is a possible magnitude for the resultant vector.
If you want to learn more, you can read:
https://brainly.com/question/18449895