Dang this is long... lolll... but for me the words are small so I can’t answer :,)
For example, if there is a L shaped sketch and you dimension from the bottom of the L to just above the horizontal part, and then you dimension the vertical part from the end point of the last dimension you'd be okay. But, if you dimensioned both of those lengths and then the total length you would be over dimensioning the sketch.
I think the answer would be C. hope i helped good luck :)