Write the next sentence in the following story.

How to graph in matlab 
Know a few things about matlab. 
Semi-colon operator: if a command is followed by a' ;' then the output will not be printed on the screen. This is trivial when the output is a short assignment, like y = 1, but becomes problematic if a large matrix is created.

Available options:
 (a). Summary operator: you see presented data together with questions. Look for the following examples of summary operators: time, volume, vhs and subdirectories..
 (b). The faster the project and the more work done, the faster the graph will be folded. Graph: divide the first group of data by the second group of data..
 (c). When the output parameters are overwritten, the object will remain in " conic form. " this means that the function of the command will only display as' ;'..
 (d). Also, any time that an output is desired, like a graph, the semicolon should be omitted. Clear command: there are a few useful command window commands... The answer should be
(d).