Identify the bug in this code snippet:

Identify the bug in this code snippet:

class A:
    def greet(self):
        print('A')

class B(A):
    def greet(self):
        super().greet()
        print('B')

class C(A):
    def greet(self):
        super().greet()
        print('C')

class D(B, C):
    def greet(self):
        super().greet()
        print('D')

d = D()
d.greet()