Final answer:
Julia means that she will give Robbie the present later.
Step-by-step explanation:
When Julia says, "Um, maybe later. I just stopped by to drop off a little present for Robbie," she means that she will give Robbie the present later.
In the given context, Julia is explaining that she doesn't have time to talk or see Robbie at that moment because she only stopped by to drop off the present. Therefore, option (B) "She will give Robbie the present later" is the correct interpretation of Julia's statement.