Sources likely to be included in an investigation plan in an auto accident case include which of the following?

A) The police department
B) Witnesses
C) Employment records
D) Hospital records
E) All of these choices are correct.

All of these sources can provide valuable information in an auto accident case. The police department can offer the official accident report, witnesses can provide firsthand accounts of the incident, employment records might be relevant for understanding the context or actions of the individuals involved (e.g., if driving is part of their job duties), and hospital records can give detailed information on the injuries sustained, which could be crucial for insurance claims or legal proceedings.