A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.LOR, PSV, TWZ, ?

Let's evaluate the position values of the letters in each group of the series (where $\text{A}=1,\text{B}=2,\dots ,\text{Z}=26$):LOR: $\text{L}(12),\text{O}(15),\text{R}(18)$ $\to$ Difference between internal letters is $+3$.PSV: $\text{P}(16),\text{S}(19),\text{V}(22)$ $\to$ Difference between internal letters is $+3$.TWZ: $\text{T}(20),\text{W}(23),\text{Z}(26)$ $\to$ Difference between internal letters is $+3$.Now let's examine the shift from the first letter of one group to the first letter of the next group:$\text{L}(12)\stackrel{+4}{\to }\text{P}(16)$$\text{P}(16)\stackrel{+4}{\to }\text{T}(20)$ Following this pattern, the first letter of the next term must be $\text{T}(20)\stackrel{+4}{\to }24$, which is X.Now, using the internal $+3$ pattern for the missing group starting with $\text{X}(24)$:Second letter: $24+3=27\to 27-26=1$, which is A.Third letter: $1+3=4$, which is D.Hence, the next term in the series is XAD.