The correct answer is C) He builds to his last and most powerful argument.
The List of Grievances starts by pointing out the king's actions that affect the colonists politically, then economically, and finally the king's war threats and acts that created casualties and had continued to jeopardize livelihoods - which can be considered the gravest accusations on the list.
The rest of the options cannot be considered correct since:
A) Jefferson only mentioned the indians at the last grievance in order to denounce their presence as a threat, rather than to protect their interests.
B) At no point on the list does Jefferson agree with the king; the list's only purpose is to undermine the king's reputation.
D) The List of Grievances is presented as evidence to support and detail Jefferson's former argument, rather than to summarize it.