$$7\times7=49\rm{cm}^{2}$$ 
What is the length of the largest square that can be made from $$50$$ one-centimetre square tile? 
[A] $$5\rm{cm}$$ 
[B] $$6\rm{cm}$$ 
[C] $$7\rm{cm}$$ 
[D] $$8\rm{cm}$$ 
[E] None of the above 