What is the simplified value of \(\sqrt {\frac{{{{\left( {0.04} \right)}^2} + {{\left( {0.21} \right)}^2} - 0.0084}}{{{{\left( {0.04} \right)}^3} + {{\left( {0.21} \right)}^3}}}}\)

• A. 0.5
• B. 2
• C. (1/0.25)
• D. (1/0.3)