It means "These are on the list, but they're not the only ones; there are others too."
option c is the correct cofficient of 3
Irrational
We know that pi is irrational (we can’t express it as a ratio of two numbers), and we are multiplying it by a rational number (-2). However -2 lots of something with infinite digits, will still have infinite digits, therefore it is irrational.
The answer would be C because he did not correct his mistakes that he had made
