"Right?" and "Don't you think?" are examples of intensifiers

When someone who is a recognized authority in a specialized area states his/her opinion, this is considered as

a. expert testimony. b. lay testimony. c. a literary quotation. d. individual opinion.

Symbols are defined as:

a. involuntary expressions of present emotion. b. voluntary expressions that stand for or represent something else. c. meanings or interpretations people assign to an event. d. a low correspondence between the sender and receiver.