Final Answer:
Gabe and Erin throw a Boeing party for Oscar's birthday, as indicated in the question, making it the specific occasion for the celebration in the storyline. Therefore, the correct answer is option 4. Oscar's birthday.
Step-by-step explanation:
Gabe and Erin throw a Boeing party for Oscar's birthday. The choice of celebrating Oscar's birthday as the occasion for the party is a significant detail in the storyline.
It not only adds a layer of character dynamics and relationships but also serves as a narrative device to drive the plot forward, creating opportunities for character interactions, developments, and potentially humorous or dramatic situations during the celebration.
The birthday party for Oscar becomes a focal point for the characters to come together, and the narrative may explore various elements such as surprises, conflicts, or resolutions arising from this event.
Therefore, the correct answer is option 4. Oscar's birthday.