Final answer:
The narrator remembers the marigolds due to a sense of guilt and shame about past actions, which are emotions that can trigger strong memories.
Step-by-step explanation:
The specific situation in the present that makes the narrator remember the marigolds is c. A sense of guilt and shame related to her past actions. These emotions are powerful catalysts for memory and are often associated with past events that may be recalled vividly when similar feelings are experienced in the present. The passages provided suggest a reflection on past events, and the natural surroundings often trigger these memories, but the marigolds themselves seem to symbolize more complex emotions and reflections tied to personal history and experiences.