Explanation:

Correct option 2: U, Q, Q, 5

Given series is - 0, 1, Z, 1, X, 2, U,   , 3, Q,   ,   ,   , L, L, L, L, L

Now lets analyse the series .

Between Z  and X there is One letter i.e. Y so there is 1 between X and Z.

Between X and U there are Two letters i.e. V,W so there is 2 between U and X .

Now, the next characters( __, 3,Q ) should follow the same rule. 

 0, 1, Z, 1, X, 2, U,  U , 3, Q,   ,   ,   , L, L, L, L, L

Now lets try to find next three characters.

We can see after Z there is 1 and there is one Letter after 1.

Next after X there is 2 and there are two Letters U,U 

Similarly, 

When there 3 then there should be three letters after 3. One is Q therefore others should be Q,Q.

 0, 1, Z, 1, X, 2, U,  U , 3, Q, Q  ,Q , __, L, L, L, L, L

Now there are 5 Ls so digit before the first L should be 5.

 0, 1, Z, 1, X, 2, U,  U , 3, Q, Q  ,Q , 5, L, L, L, L, L

So, We added U, Q, Q, 5 in the given series.