$a,b,c$ are natural no and equations $x^2-5x+a=0,x^2-6x+b=0,x^2-8x+c=0$ have exactly one root in common and common root is also a natural no.The common root is :

Question

$\begin{array}{1 1}(A)\;\text{1 or 2}&(B)\;\text{3 or 4}\\(C)\;\text{1 or 2 or 3}&(D)\;\text{1 or 2 or 3 or 4}\end{array} $