Final answer:
Katrina, as a rule-utilitarian, likely believes that requiring minors to notify a parent before an abortion would minimize risks to minors and maximize overall happiness by promoting informed decision-making and protecting familial relationships.
Step-by-step explanation:
If Katrina is a rule-utilitarian and believes that the rule stating "Girls under the age of eighteen should not be permitted to have abortions without notifying a parent or guardian" would maximize happiness, the best reason for Katrina's view could be c) Minimizing potential risks to minors. Rule utilitarians seek to establish moral rules that will maximize happiness if followed consistently. In this case, the rule could be seen as protecting young individuals from making decisions that could have significant and lasting impacts on their health and wellbeing without the support or counsel of a responsible adult. Another consideration is that by setting such a rule, it may also preserve trust and stability within familial relationships and thereby contribute to the overall utility. Moreover, since Katrina's views are in line with rule utilitarianism, they seek to create long-term positive outcomes through consistent application of rules, rather than making decisions on a case-by-case basis as in act utilitarianism.