Insert the Missing Code in the Following Code Fragment

Multiple Choice

Insert the missing code in the following code fragment. This fragment is intended to initialize an instance variable.
Public class Vehicle
{
Int numAxles;
Public Vehicle(int axles)
{
NumAxles = axles;
}
Public Vehicle()
{
_________;
}
}
Which of the following lines of code will allow the second constructor to call the first constructor?

A) this. numAxles(0) ;
B) this(0) ;
C) this(axles) ;
D) this(numAxles) ;