Critical Reasoning

Instead of blaming an automobile accident on driver error, insurance companies should first try to figure out why the error was made by analyzing flaws in road design, automobile designs and in criteria to determine eligibility for a driver's license. Only then will the insurance companies be able to effectively issue guidelines to prevent future accidents, instead of merely punishing the incidental driver.

Which of the following is a presupposition of the argument above?

A) Driver error is not a significant factor in most automobile accidents.
B) Automobile manufacturers should be the agents who investigate automobile accidents and not insurance companies.
C) Stricter government regulation of the automobile and highway construction industries would make automobile travel safer.
D) Investigation of automobile accidents should contribute to the prevention of future accidents.
E) Most drivers who make errors in driving repeat those errors unless they are retrained.

I came across this somewhere on the web.
The answer is E
I didn't get it though.

Please explain!

Thank you.