Which Country Has the Strongest GDP Per Capita

Which country has the strongest GDP per capita:
W= GDP of $152 billion and a total population of 54,553,000
X = GDP of $400 billion and a total population of 21,900,000
Y= GDP of $595 billion and a total population of 38,500,000
Z = GDP of $ 628 billion and a total population of 43,655,000

A) Country W
B) Country X
C) Country Z
D) Country X and Y are equal