Question $16/30$

What is the expected output of the following code?

collection $=[]$

collection. append $(1)$

collection.insert $(0,2)$

duplicate $=$ collection $[$: $]$

duplicate.append $(3)$

print$($len$($collection$)+$ len$($duplicate$))$

$6$

$5$

The code raises an exception and outputs nothing.

$4$