Final answer:
The financial officer of a church with funds invested in the chemical company is the least likely to be among the "watchdog" groups monitoring Metro Chemical Corporation.
Step-by-step explanation:
The least likely group to be among the "watchdog" groups monitoring Metro Chemical Corporation would be the financial officer of a church with funds invested in the chemical company. The other options, such as overseers from the World Trade Organization (WTO), a student of environmental engineering, and the president of the union representing the workers at the chemical company, are more likely to have an interest in monitoring the company's involvement in ethical and social responsibility policies.