If the roots of the equation `a(b - c)x^2 + b(c- a)x+ c(a-b)=0` are equal, then which of the following is true?
यदि समीकरण a(b - c)x^2 + b(c- a)x+ c(a-b)=0` के मूल बराबर है, तो निम्नलिखित में से कौन सा सही है?

Options

A. `b = (a + c)//ac`
B. `2//b = (1//a) + (1//c)`
C. `2b = (1//a) + (1//c)`
D. `abc = ab + bc + ca`