The correct answer is: A. 0° and 90°
The resultant of two forces is the single force that would produce the same effect as the two forces acting together. The resultant of two forces can be found by using the parallelogram law of forces.
The parallelogram law of forces states that the resultant of two forces is represented by the diagonal of the parallelogram formed by the two forces.
The angle between two forces is the angle between the two lines representing the forces.
The resultant of two forces is a minimum when the two forces are in the same direction. The resultant of two forces is a maximum when the two forces are in opposite directions.
Therefore, the angles between two forces to make their resultant a minimum and a maximum respectively are 0° and 90°.
Option B is incorrect because the resultant of two forces is a maximum when the two forces are in opposite directions.
Option C is incorrect because the resultant of two forces is a minimum when the two forces are in the same direction.
Option D is incorrect because the resultant of two forces is not a maximum when the two forces are in the same direction.