A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.BCD, HIJ, OPQ, ?

Let's track the numerical positional values of the first letters of each triplet in the series:First letter of BCD is $\text{B}=2$ First letter of HIJ is $\text{H}=8$ First letter of OPQ is $\text{O}=15$ Let's look at the differences between successive starting letters:From $\text{B}(2)$ to $\text{H}(8)\to +6$ From $\text{H}(8)to\text{O}(15)\to +7$ Following this increasing gap pattern ($+6,+7,+8$), the first letter of the next group should be:$\text{O}(15)\stackrel{+8}{\to }23$, which corresponds to the letter W.Since each group consists of three consecutive letters (B-C-D, H-I-J, O-P-Q), the group starting with W will be WXY.