An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the bulb is \[5\times {{10}^{-4}}\] phot (lumen/cm2). The line joining the bulb to the point makes an angle of 60o with the normal to the surface. The intensity of the bulb in candela is [IIT-JEE 1980; CPMT 1991]

• A.            \[40\sqrt{3}\]                      
• B.            40
• C.            20  
• D.            \[40\times {{10}^{-4}}\]