The position vectors (in km) of three towns are rA=3i^−2j^, rB=−1i^+4j^, and rC=5i^+j^. A vehicle starts from A, travels to B, and then to C. What is the ratio of the total distance travelled to the magnitude of the resultant displacement from A to C (rounded to one decimal place)?
a) 3.0
b) 3.9
c) 4.5
d) 2.8