Respuesta :
2018 because December is still in the same year 1 year= 12 months and December is the 12 month so it is the last month in 2018.
2019 starts in the next January. December would still be in 2018.
2018 because December is still in the same year 1 year= 12 months and December is the 12 month so it is the last month in 2018.