Select the option that can be used as a one-word substitute for the given group of words.
A non-professional who is inept at a particular activity

Correct option is B

The correct one-word for the given group of words is (b) Amateur.
Explanation:
An amateur refers to a person who engages in a pursuit, especially a sport or art, on an unpaid basis or non-professionally, often lacking skill. (ग़ैर-पेशेवर, नौसिखिया)
Example: Though he plays the violin well, he is just an amateur, not a trained musician.
Meanings of the given other options:
· (a) Expert: A person who is highly skilled or knowledgeable in a particular area (विशेषज्ञ)
· (c) Director: A person who manages or guides an organization or department (निर्देशक)
· (d) Fatalist: A person who believes that all events are predetermined and inevitable (नियतिवादी)