$$0.1\times 0.2\times 0.3=(0.1\times 0.2)\times 0.3=0.02\times 0.3=0.006$$. Therefore, the answer is $$\rm B$$. 
$$0.1\times 0.2\times 0.3=$$~\uline{~~~~~~~~~~}~. 
  $$0.0006$$ 
  $$0.006$$ 
  $$0.06$$ 
  $$0.6$$ 