Answer:
The correct answer is: Sibling rivalry can creep into even the most peaceful families.
Step-by-step explanation:
The introduction is an essential part of an essay. In essays, introductions might cover three important parts: hook, background, and thesis. Writing an essay on sibling rivalry could have "sibling rivalry can creep into even the most peaceful families" as the opening sentence, since it establishes a statement that can be familiar or interesting to the reader, therefore, working as a hook.