Option 1: 1.405 -> Incorrect calculation of the ratio.
Option 2: 1.046 -> This would result from dividing Real GDP by Nominal GDP incorrectly.
Option 3: 1.45 -> Close but rounded down too early.
Option 4: 1.46 -> Correct ratio of Nominal GDP to Real GDP.
Hence, Option 4: 1.46 -> The GDP deflator is calculated as (Nominal GDP / Real GDP). Using the given values: 1900 / 1300 = 1.4615, which rounds to 1.46. The GDP deflator measures the price level of all domestically produced final goods and services in an economy, showing how much prices have changed from the base year. -> correct