the good answer of this python quiz is "3"; can you explain me why doesn't "2"? a=[1,2] ; b=a ; a.append (3) ; print(len(b))

Question

Questionable quiz answer !!!!

Answer 1

Because both b and a are referring to same list i.e [1,2,3]
Hence ans is 3

Answer 2

~ swim ~
So , in this case :
a=5
b=a
a=8
b follow the change in a or keep the value 5 ?