Final answer:
Owing a lot of money and having many lines of credit can harm your credit score, while making steady payments is beneficial.
Step-by-step explanation:
The statements that describe actions harmful to your credit score are I and II. Owing a lot of money can negatively affect your credit score because it indicates a high level of debt and potential risk for lenders. Having many lines of credit can also harm your credit score because it increases the likelihood of accumulating debt or missing payments.
On the other hand, making steady payments (statement III) is actually a positive action that can help improve your credit score. Consistently paying your bills on time shows lenders that you are responsible and trustworthy.
Learn more about Actions that impact credit score