A claim is something that can be defended with evidence while an opinion is just what you believe and does not require any evidence
“When thinking” is the right answer (the definition of retrospect is “a survey or review of a past course of events or period of time”. So “when thinking “ is most likely the right answer.
The answer you are looking for is A, member. The other 3 all have to do with being mindful! While a member just refers to a person. Not to mention there is no "or" in member!
Hope this helps!
