The resultant of ` vec(a)` and ` vec(b)` makes `alpha` with `vec(a)` and `beta` with `vec(b)`, then (a,b represent magnitudes of respective vectors) :
A. `alpha lt beta`
B. `alpha lt beta if a lt b`
C. `alpha lt beta if a gt b`
D. `alpha lt beta if a =b`
