Find the Missing Monomial, Factor or Term $(?)^{2}=36 x^{2}-12 x+1$ A) $6 x-1$

Multiple Choice

Find the missing monomial, factor or term.
- $(?) ^{2}=36 x^{2}-12 x+1$

A) $6 x-1$
B) $6 x+1$
C) $x-1$
D) $6 x-6$