Chapter 3, Problem 3.2QQ

The magnitudes of two vectors $\stackrel{\to }{A}$ and $\stackrel{\to }{B}$ are A = 12 units and B = 8 units. Which pair of numbers represents the largest and smallest possible values for the magnitude of the resultant vector $\stackrel{\to }{R}=\stackrel{\to }{A}+\stackrel{\to }{B}$? (a) 14.4 units, 4 units (b) 12 units, 8 units (c) 20 units, 4 units (d) none of these answers