There are an odd number of positions, the assembly area should be in the mid-point, $$\left( 151+1 \right)\div 2=76$$, that is, the $$76^{}\text{th}$$ traffic ambassador\textquotesingle s position 
$$151$$ traffic ambassadors lined up neatly in a straight line (at equal distances from each other) on a highway to promote traffic laws. After completing their task, at which position of the highway should they assemble in order to minimise their total walking distance from their respective positions to the assembly area? ． 
A. $$75^{}\text{th}$$ traffic ambassador\textquotesingle s position 
B. $$76^{}\text{th}$$ traffic ambassador\textquotesingle s position 
C. Between the $$75^{}\text{th}$$ and $$76^{}\text{th}$$ traffic ambassadors\textquotesingle~positions 
D. Any position on the highway 