maçã should be clearly distinguishable from massa: http://translate.google.com/#pt/en/uma%20massa.%20%0Auma%20ma%C3%A7%C3%A3. (click play sound)
The problem with many of the exercises is that they're phrased in a way that makes more sense in the context of some prior statement. In this case, "mass" is a great word to create a picture of a huge mindless lump--e.g., "People were swarming around the courtroom door, impatient for the coming spectacle to begin. All of a sudden, the doors opened, and the mass surged into the court."
I thing the best translation is "The throng entered the court", it sounds adequately mediaevil.