Final answer:
Jim's reaction signifies an event that Della should have anticipated.
Step-by-step explanation:
Jim's reaction signifies A. An event that Della should have anticipated. In the text provided, there are no explicit references to Jim being afraid to confide in Della (option B). Additionally, there is no indication of an unusual revelation for Della (option C) or the realization that Jim lacks a gift for Della (option D). However, based on the context, it can be inferred that Della's action or behavior might have led to Jim's reaction, suggesting that it is an event that she should have expected.