Mark owns a furniture store in Winterville. He relies on online customer reviews to find out what customers like about the line of furniture he carries and what customers find unsatisfactory about the service at his store. Which of the following is true about the feedback process of communication that could assist Mark?

a. Feedback takes place before the process of decoding.
b. With the increase in online advertising and social media, marketers are able to get more feedback via the internet.
c. Feedback cannot be nonverbal.
d. Indirect feedback does not help mass communicators to decide whether to continue, modify, or drop a message.