Final answer:
The word 'peripheral' in the sentence suggests that Marci considered the task of picking out a new paint color for her living room to be unimportant compared to planning her daughter's wedding.
Step-by-step explanation:
In the context provided, Marci considered choosing a new paint color for her living room as peripheral in comparison to her daughter's wedding planning. The correct definition for 'peripheral' in this sentence is c. unimportant.
This means that picking out a new paint color was not a central or significant concern to Marci at that moment, implying that her focus was directed more towards the important event, which in this case was her daughter's wedding.