Final answer:
The decline of the Quebec Nordiques NHL team can be attributed to marketing mismanagement by the team owners.
Step-by-step explanation:
The best explanation for the decline of the Quebec Nordiques NHL team was c) marketing mismanagement by the team owners.
The team owners' poor management decisions, including their failure to effectively market the team, contributed to the decline and eventual relocation of the Quebec Nordiques.
For example, they did not invest in promoting the team, attracting fans, or generating sufficient revenue. This lack of marketing efforts affected the team's popularity and financial stability, ultimately leading to the team's decline.