An appliance salesperson may have more influence than an ad because the salesperson can interact with and answer questions that the buyer may have. In terms of sources of influence, this shows that when certain marketing sources $($like a salesperson$)$ provide information, there is a higher chance of $$ than when other marketing sources $($like an ad$)$ provide similar information.

a$.$ opinion leadership

b$.$ credibility

c$.$ two$-$way communication

d$.$ valence

e$.$ verbal communication