Adef vfunc(a,b): def vfunc(a, b): def vfunc(a, b): Ddef vfunc(a,b=2):

The first line contains a syntax error due to the missing colon at the end of the line. The correct syntax would be:

def vfunc(a, b):

The second line is a duplicate of the first line and should be removed.

The third line is also a duplicate of the first line and should be removed.

The fourth line is a valid function definition with a default value of 2 for the parameter b.