Given the Following Recursive Function Definition, What Is the Stopping

Given the following recursive function definition, what is the stopping case?
Void towerschar source, char dest, char help, int numDisks)
{
IfnumDisks<1)
{
Return;
}
Else
{
Towerssource,help,dest,numDisks-1) ;
Cout << "Move disk from " << source << " to " <<dest<<endl;
Towershelp,dest,source,numDisks-1) ;
}
}

A) numDisks == 1
B) numDisks >1
C) numDisks < 1
D) numDisks =0