The answer is C because it is a compound sentence
Ellas (ensenan) Administracion de empresas. Yo (necesito) preparer la tarea. Hector y yo (compramos) en la libreria. Me (gusta) bailar los sabados. Enrique (desea) escuchar musica. A ti te (gusta) la psicologia?
Hey there!
The direct translation is, "Three friends minus two friends. How many friends do you have?"
The answer would be, "Tengo un amigo."
Hope this helps!
Have a great day! :)