Answer:
I am pretty sure it is the C.
Explanation:
The reasons is that A and D are broken apart too much and B is just a run on sentence.
to make connections to other texts
Subsequent is a time later or more recent than.
He discover that he might suffer from some mental disorder causing him to react aggressively and with no limits at all,suffering afterwards from the aftermath of his own actions therefore he decides to keep a journal about it for research....