Question $4(1$ point$)$

Why will this code fail $($assume $a$ is a list of integers$)$:

$a[len(a)]=42$

Because it should be

$a(len[a])=42$

Because the length of a list is never a valid index for that list.

It won't fail, but it won't do anything.

It won't fail; it will add a new element with the value $42$ to the end of the list.