Answer "As per which of these calendars are we in the year 2018?"

Answer of Quiz :  As per which of these calendars are we in the year 2018?

Question 2 of 6 from  Amazon January Quiz -  As per which of these calendars are we in the year 2018? 

Option 1 : Byzantine calendar

Option 2 : Julian calendar

Option 3 :  Vikram Samvat

Option 4 : Gregorian calendar

Answer of Amazon Quiz Time: Option 4 : Gregorian calendar

Select 4th Option is a correct answer of this Question 

About Gregorian calendar From Wiki  - It was a refinement to the Julian calendar[3] involving an approximately 0.002% correction in the length of the calendar year. The motivation for the reform was to stop the drift of the calendar with respect to the equinoxes and solstices—particularly the northern vernal equinox, which helps set the date for Easter. Transition to the Gregorian calendar would restore the holiday to the time of the year in which it was celebrated when introduced by the early Church. The reform was adopted initially by the Catholic countries of Europe. Protestants and Eastern Orthodox countries continued to use the traditional Julian calendar and adopted the Gregorian reform, one by one, after a time, at least for civil purposes and for the sake of convenience in international trade. The last European country to adopt the reform was Greece, in 1923. Many (but not all) countries that have traditionally used the Julian calendar, or the Islamic or other religious calendars, have come to adopt the Gregorian calendar for civil purposes.