A Public Issue is an offer made to the general public to subscribe to the share capital of a company, open to any investor at large, resulting in allotment to 50 or more persons.
Source: Issue of Shares, Chapter 3
The examiner expects two key elements: (1) it is an offer open to the general public (not a select group), and (2) allotment is made to 50 or more persons. Including both earns full marks. Do not confuse with private placement (fewer than 50 persons).