Given a string of binary bits str$,$

$-$ the least significant bit of str is the right$-$most bit;

$-$ and the most significant bit of str is the left$-$most bit.

E$.$g$.,$ for the string str $="001101",$ the most significant bit is $0,$ the least significant bit is $1.$

Consider the code below:

str $=$ input$("$input a binary string"$)$

k $=$ len$($str$)$

Which of the following is$/$are correct?

Please choose All correct answer$($s$).$ Note: At least one of them is correct.