$91\times5-(100+99+98+97)=61$. 
A test is with a full score of $100$ points. Five students in a group wants to reach an average of $91$ points. If everyone scores a different whole number, the lowest score among them could be~\uline{~~~~~~~~~~}~. 
Options:
a: $$60$$ 
b: $$61$$ 
c: $$67$$ 
d: $$70$$ 
e: $$71$$ 