The slope of the function\(f\left( x \right) = \left\{ {\begin{array}{*{20}{c}} {{x^2}\sin \left( {\frac{1}{x}} \right),}&{x \ne 0}\\ {0,}&{x = 0} \end{array}} \right.\) ?

• A. 1
• B. 0
• C. -1
• D. None