The word 'flu' is shorthand forAFluorescent Light UnitBFluid Level UpCInfluenzaDFluorescent Lighting UpgradeAnswer: C. Influenza Read Explanation: Flu stands for Influenza /പകർച്ചവ്യാധി. It is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and sometimes the lungs.Read more in App