Correct Answer: DWRQRFTW

Solution : Given:
TR_ _QT _ EW _T_ _WQ _ RG_Q

To fill the series, we have to divide the series – TR_ _Q / T _ EW _ / T_ _WQ / _ RG_Q
Let's check the given options –
First option: DWSQSFTW; TR D W Q / T S EW Q / T S F WQ / T RG W Q; (No repeated pattern found.)
Second option: DWSQRFTW; TR D W Q / T S EW Q / T R F WQ / T RG W Q; (No repeated pattern found.)
Third option: DWRQRFTW; TR D W Q / T R EW Q / T R F WQ / T RG W Q; (TRWQ is being repeated and the third letter of each part is in sequential alphabetical order.)
In TR D WQ, D + 1 = E (TR E WQ)
In TR E WQ, E + 1 = F (TR F WQ)
In TR F WQ, F + 1 = G (TR G WQ)
Fourth option: EWRQRFTW; TR E W Q / T R EW Q / T R F WQ / T RG W Q; (No repeated pattern found.)

So, the sequence is TRDWQTREWQTRFWQTRGWQ. Hence, the third option is correct.