Task: Question Answering
Input (English): Problem: if o is the center of the circle in the figure above and the area of the unshaded sector is 5 , what is the area of the shaded region ? 
Options: ['a ) 25 / √ π', 'b ) 30 / √ π', 'c ) 20', 'd ) 25', 'e ) 30']
Output (English): d