An asteroid has a perihelion (the orbit's closest approach to the sun) of 1.5 AU and a period of revolution of 8.0 y. What is its greatest distance from the sun (its aphelion)?
选项：

A:8.0 AU;
B:6.5 AU;
C:4.0 AU;
D:2.5 AU;
E:3.5 AU;
F:4.5 AU; G:5.5 AU