The correct answers are My oldest sister, Maria, is a pilot/ My two best friends, Tory and Monica, met me at the movies/ Bulldogs, which I love, are the cutest!
Step-by-step explanation:
The general punctuation rule for a nonrestrictive modifier is that these should be enclosed by commas. Moreover, this type of modifier describes a noun but the modifier is not essential, which means it can be omitted. According to this, there are three sentences with a non-essential modifier punctuated correctly:
1. My oldest sister, Maria, is a pilot- In this sentence, the modifier "Maria" can be omitted because there is only one oldest sister; also, this is enclosed by commas, which makes it a correct answer
2. My two best friends, Tory and Monica, met me at the movies- Similarly, in this sentence, the modifier "Tory and Monica", can be omitted and this is correctly punctuated, therefore this is also a correct answer.
3. Bulldogs, which I love, are the cutest! - In this sentence the main idea is to express bulldogs are the cutest, thus, the modifier is non-essential and it has been punctuated correctly. This is the third answer.