In the sequence SCD, TEF, UGH, __, WKL, the first letter of each group progresses consecutively through the alphabet: S, T, U, then the missing one should be V, followed by W.
The two-letter pairs also progress consecutively: CD, EF, GH, then the missing pair should be IJ, followed by KL, each pair advancing two letters further along the alphabet.
Combining the missing first letter V with the missing pair IJ gives VIJ, matching option 3.