How does Lincoln use ethos is this excerpt?

Now, therefore I, Abraham Lincoln, President of the United States, by virtue of the power in me vested as commander in chief, of the army and navy of the United states in time of actual armed rebellion against the authority and government of the United states and as a fit and necessary war measure for suppressing said rebellion, do on this first day of January, ...

ABy using facts and statistics to show his logic

BBy citing the office to which he was elected

CBy urging the audience to refuse to accept slavery

DBy citing other officials who support his views