Source factors that influence how persuasive an argument can be include all of the following except

a.
length of argument
b.
trustworthiness
c.
level of expertise
d.
attractiveness

D.  attractiveness

Explanation:

An argument is a state of dispute or controversy or expression of opinion for some idea that goes against the other idea. An argument generally develops due to disagreement between two individuals, each of which supports the facts with own point of view.

The attractiveness is the factor which will not involve the argument this is because of the fact that if the two individuals are obeying each other opinions or attracted by each others opinions then their will be no reason for argument.