The man who is now Municipal Commissioner worked as ________________. A. the security guard at a university B. a security guard at the university C. a security guard at university D. the security guard at the university

GATE 2016 · General Aptitude · Articles · medium

Answer: B. a security guard at the university

1. Article before 'security guard': The man's past role as a guard is introduced for the first time and is not a unique designation. Use 'a' (indefinite). Options A and D use 'the security guard', which would imply a specific, pre-identified guard — incorrect here.
2. Article before 'university': The university is referred to as a specific institution (understood from context). 'A university' is unspecified; 'the university' points to the particular university associated with the story. Option C has no article before 'university', which is grammatically incorrect for a singular countable noun in this context.
3. Select correct answer: Combining both rules: 'a security guard' (indefinite job role) + 'at the university' (specific institution) => Option B: 'a security guard at the university'.