The correct answer is A. Superficial.
A superficial knowledge is a basic understanding of something. It is a general knowledge of a subject that is not very detailed or in-depth.
A wide knowledge is a broad understanding of a subject. It is a general knowledge of a subject that covers many different aspects.
A profound knowledge is a deep understanding of something. It is a detailed and in-depth knowledge of a subject.
A sufficient knowledge is enough knowledge to understand and do something. It is a basic understanding of a
subject that is enough to get the job done.An excessive knowledge is
too much knowledge about something. It is a detailed and in-depth knowledge of a subject that is more than is needed.In the given question, the speaker is saying that the person has a basic understanding of the subject. This means that the person has a superficial knowledge of the subject.