The word "reserved" is the most suitable choice to fill in the blank because it indicates a lack of outward expression or enthusiasm. If someone becomes reserved in a conversation about a certain topic, it means they become more restrained, quiet, or less willing to openly share their thoughts or feelings. In the given context, it suggests that the person's demeanor changed to a more restrained or withdrawn state when discussing her father.

Unconditional dedication" implies unwavering commitment and loyalty to the company regardless of circumstances. While support, attachment, and love can also be relevant in the context of an employee's relationship with their company, "dedication" specifically captures the idea of steadfast loyalty and commitment. Therefore, option 2 is the best fit for the sentence.

The most appropriate option to fill in the blank is:

Official

Explanation: In this context, the word "official" suggests that the medicine being administered is recognized and approved by the relevant authorities or medical professionals. It implies that the medicine is legitimate and prescribed within the official protocols of medical practice.

The other options do not fit well in the context:

"Eminent" means distinguished or noteworthy, but it doesn't directly relate to medicine in this context.

"Alternative" suggests a different option, which may not align with the doctor's directive.

Insightful" refers to having a deep understanding or perception, which doesn't make sense in the context of administering medicine.