The unnecesary qualifiers that need to be removed are: b) kind of.
Explanation:
To understand this we need to be very strict. First of all kind of doesn't say a close perspective or opinion. It is misleading and as a cause of it is only used in informal scenarios. It is the same as saying so so or less than better. It doesn't express a meaningful idea. The concept of adding it is futile and it would not work on formal environments in which clarity is sought. So, that is why b) option is the correct answer.