Scanned images are by nature raster files. Vector images are totally different. On the web, you would want to use a raster file format (JPG, PNG, GIF,...).
Answer A is nonsense, in fact, you want to use raster files all the times on the web.
Answer B is also nonsense. A scanner will produce a raster file as output.
Answer C is true but you wouldn't want Trent to make that conversion.
Answer D is not true, since scanners will natively output a raster file format.
So I'd go for C.
