How can the separated DNA fragments be visualised after gel electrophoresis?

By staining with Copper sulphate solution followed by gamma rays exposure By staining with ethidium bromide followed by gamma rays exposure By staining with ethidium bromide followed by UV rays exposure By staining with bromophenol blue followed by UV rays exposure

By staining with ethidium bromide followed by UV rays exposure

The separated DNA fragments after gel electrophoresis can be visualised only by staining with ethidium bromide followed by the exposure of UV rays.