Explanation:
in a 4-digit number : how many 0 can there be ?
can there be five 0s ?
no, how could there be ? there is no space for five 0s, when there are only 4 positions for digits.
it is said that there are no restrictions on the digits.
so, any digit can occur at any position.
that means simply that there can be
no 0s : e.g. 1234
one 0 : e.g. 1204
two 0s : e.g. 1030
three 0s : e.g. 0030 or 7000 ...
four 0s - only one possibility : 0000
so, the possible values for X are
0, 1, 2, 3, 4
please pick the corresponding answer in your list, as you clearly made some typos there. I cannot tell the difference between some of the options you provided.
the X value for 1020 is 2
the X value for 2478 is 0
the X value for 7130 is 1
if there are more numbers, you did not list them.