\[\left[ \left\{ 1+\frac{1}{20+\frac{1}{20}} \right\}\times \left\{ 1+\frac{1}{20+\frac{1}{20}} \right\}- \right.\]\[\left. \left\{ 1-\frac{1}{20+\frac{1}{20}} \right\}\times \left\{ 1-\frac{1}{20+\frac{1}{20}} \right\} \right]\div \]\[\left[ \left\{ 1+\frac{1}{20+\frac{1}{20}} \right\}+\left\{ 1-\frac{1}{20+\frac{1}{20}} \right\} \right]\]

• A. \[\frac{40}{401}\]                     
• B. \[\frac{90}{401}\]
• C. \[\frac{400}{401}\]                               
• D. \[\frac{401}{400}\]