The following are the meanings of the word trace:
(i) Follow, discover, or ascertain the course of development of something
(ii) Make a mark or lines on a surface
(iii) To go back over again
(iv) Pursue or chase relentlessly
(v) Find or discover through investigation
(vi) Make one’s course or travel along a path, travel or pass over, around, or along
(vii) Read with difficulty
The closest meaning of the word ‘trace’ in the text is ‘to find or discover through investigation’.