A PERSON WHO STAYS IN THE COUNTRY FOR AN ESTABLISHED 183 DAYS IN RUSSIA OR MORE PER YEAR IS a. a citizen b. a tax agent c. a tax resident d. a taxpayer

The correct answer is c. a tax resident.According to the tax laws in Russia, a person who stays in the country for an established 183 days or more in a calendar year is considered a tax resident. This means that they are subject to taxation on their worldwide income, regardless of whether it is earned within Russia or outside of it.Being a tax resident does not necessarily mean that the person is a citizen of Russia. Citizenship and tax residency are two separate concepts. A person can be a tax resident in Russia without being a citizen, and vice versa.The terms "tax agent" and "taxpayer" are not directly related to the concept of tax residency. A tax agent is a person or a company that provides tax-related services to individuals or businesses, while a taxpayer is a person or an entity that is liable to pay taxes.Therefore, the correct answer is c. a tax resident.