A black swan event is an unpredictable occurrence with significant consequences. In the short term, such events often lead to market volatility and a flight to quality. Investors with suitable time horizons and risk tolerance may respond by making tactical adjustments to their portfolios. These changes are typically short-term and reactive.

• Option B (Sector-specific adjustments) is incorrect because it pertains to medium-term impacts of geopolitical risks, which affect specific sectors more than others.

• Option C (Strategic asset allocation changes) is incorrect as it relates to long-term impacts, where risks influence environmental, social, and governance factors, requiring adjustments over a prolonged period. Immediate portfolio impacts are limited in such cases.