A virus can do many things from burn up your hard drive to just annoy you with ads. the best thing you can do if you think you have one is take it to a professional
An app launcher replaces the stock user interface for organizing the home screen and app icons predominantly in the Android world; however, they are also available for jailbroken iPhones (see iPhone jailbreaking and Cydia). See Launchpad.
I guess the best option is letter D.
In 1972, Gordon Bell formulated Bell's Law, which states a new computer class forms roughly each decade establishing a new industry.
All I will say is good luck. because it can be very difficult to find someone that is willing to do this.