Observe the following. \[m=3\times 2\times {{5}^{2}}\] \[n={{3}^{2}}\times {{2}^{2}}\times 5\] \[p={{3}^{2}}\times {{2}^{2}}\times {{5}^{2}}\] What is the G.C.D of m, n and p?

• A.  30                  
• B.    150                
• C.    45     
• D.    50