Final answer:
A conflict of interest arises when personal interests may interfere with professional duties. Among the given options, a provincial cabinet minister voting on a subdivision on land they no longer own is not a conflict of interest unless prior knowledge of development existed. Avoiding conflicts is crucial for ethical governance and maintaining public trust.
Step-by-step explanation:
A conflict of interest occurs when an individual's personal interests could compromise their decision-making in an official capacity. The question presents different scenarios and asks which one is not a conflict of interest:
- A municipal councilor voting for the city to purchase a building they own.
- A provincial cabinet minister voting for a subdivision to be built on land they previously owned.
- A school trustee voting on a contract for teachers when the trustee's spouse is a teacher.
- A member of parliament investing in a firm that later receives a government contract.
Each scenario involves a potential conflict except for option b, as the conflict would have ceased when the minister no longer owned the land in question. However, if the minister had prior knowledge that the land would be developed, this could still pose a conflict. It is important for representatives to avoid such conflicts to maintain public trust and ensure ethical governance.