In which of the following cases, a parabolic reflector primary radiator is said to be ideal feed?

• A. The entire reflector is illuminated with no radiation in unwanted direction when feed radiated entire energy towards it
• B. Some part of reflector is illuminated with no radiation in unwanted direction when feed radiated entire energy towards it
• C. Some part of reflector is illuminated with radiation in unwanted direction when feed radiated entire energy towards it
• D. The entire reflector is illuminated with small radiation in unwanted direction when feed radiated entire energy towards it