for 0000 which has length 4 we have to concat with

length 0 + length 4

length 1+ length 3

length 2+ length 2

now here in the language smallest string is length 2 which is “01” or “10” so by concatenate them we cant get “0000” and L itself does not contain “0000”.

option c the string “111101” is present in the language ,it has even length and odd no of zero . So it will be in L*.

Option D is also not in the L* as it can be generate by concate either