Final answer:
The correct answer is c) resist, meaning Mildred couldn't refrain from opening the package. 'Resist' is the appropriate term for describing the struggle against a tempting action.
Step-by-step explanation:
Mildred could not resist her desire to open the package immediately, even though it read, "Do not open before Christmas!" The correct answer to the question is c) resist. To resist means to withstand the action or effect of something; in this context, it refers to Mildred's inability to refrain from opening the package.
The other options given, such as suppress, convey, and express, do not accurately describe the struggle to avoid doing something that is tempting.
In the provided reference, we encounter a similar struggle where emotions and impulses need to be managed in the context of fairness and freedom.