The correct option is D Statements and Illustration
There is no comparisons present in the passage. So option A)can be eliminated. Chronological order means the order of dates of past events. There is no record in this passage. So option B)can be eliminated. Similarly there are no causes and results . So option D) can be eliminated.
(C) is the right answer. The passage consists of statements and
illustrations. There are statements about diamonds, types of diamond,
their value and characteristic. And there are illustrations about
retrieving of diamonds from mines and the process of cutting and
polishing them.