Final answer:
Nick's great news is that they are having a baby together, making the correct answer choice 4) We're having a baby. The reference texts provided relate to aspects of relationships and life changes but do not directly pertain to the topic of announcing a pregnancy.
Step-by-step explanation:
The great news being referred to by Nick is that they are having a baby together. This information is clearly provided in the statement 'It's okay, we're having a baby together.' Therefore, the correct answer to Nick's question about the great news is option 4) We're having a baby.
In the context of the provided reference texts, each passage discusses different aspects of relationships, such as the language used to describe them and the life changes they bring. However, none of these passages specifically address the topic of announcing a pregnancy, which is the context of Nick's statement about the great news.