The correct option is C last year's results
The underlined phrase "last year's" does not tell us what of last year has been repeated this year. It sounds incomplete, so we need to change it, which makes option A incorrect. Similarly, when we replace the phrase with option B, 'the previous year' also does not specify what of the previous year is repeated, and using this also makes the sentence sound incomplete hence option B is incorrect. In option C 'that' is a demonstrative that modifies a noun that has been mentioned before, since there isn't any noun mentioned before the phrase, this option cannot be used hence it's incorrect. In option D, the phrase tells us what from the last year has been repeated this year as well, the 'results' of last year were repeated this year. Hence using this makes the sentence sound complete option D is correct.