It's definitely repetition. Just finished the question and it was correct :-)
It's when someone makes a fast and false conclusion because they only know the general idea of the thing they are concluding, and not all of the facts, if that makes sense. It's kind of like a stereotype, automatically assuming that someone is a certain way just because they participate in a certain sport, for example.
The first choice (Using a sharp knife, cut each piece of bread diagonally into two equal pieces) It gives the reader a clear and detailed visual of how he is making the food
Hope this helps!!