According to a recent survey, the growth of facility investment tends to fall there is a presidential election. A. which
B. in order that
C. when
D. on behalf of

Option C (when), is the answer.

the correct answer is:

this is an example of the writer telling through description rather than showing through dialogue.

sometimes writers like to explain explicitely what's happening instead of adding dialogues of the situations., which is the case in this passage,