The Break options allow you to break line features at a given segment into two. The break is created by adding the new feature comma code, normally N, to the second point of the segment.
The Indicate option allows you to break a line by indicating the segment of the line feature where the break is to occur. Note that you cannot break a closed feature so if the indicated feature is closed, you will be asked if you want to open it before the break can take place.
The Strike option allows you to break several features using a strike line. You will be asked to indicate the start and end points of a strike line and appropriate breaks will be created for line features that intersect the strike line.
The Distance option allows you to break all line features where the length of a feature segment is greater than a given value. If this includes closed features, these will be opened.