Final answer:
The answer is 'Venture', which adds a letter to the name of a country (not provided) to form a word describing a fully equipped business opportunity, relating to the concept of venture capital.
Step-by-step explanation:
If you add a letter to the country shown here, to describe a fully equipped business opportunity, the correct answer is b) Venture. The country in question is not provided, but the word venture matches the description of a fully equipped business opportunity, as in the definition of venture capital, which refers to funding that investors provide to startup companies and small businesses that are believed to have long-term growth potential. None of the other options, such as varnish, vintage, or version, fit the context of a business opportunity.