The electirc field strength at a distance rr from the centre of a charged sphere of radius r is E. If r > R, how much work will be done in bringing a test charge q₀ from infinity to that point, is

(1) q₀RE  
(2) 1/2 q₀RE        
(3) q₀ r E       
(4) 1/2 q₀ r E