Match the two lists and choose the correct answer from the code given below:

List-I                                List-II 

(w) Digital Counter        (i) Measurement of harmonics 

(x) Schering bridge        ii) Measurement of frequency 

(y) Megger                        (iii) Measurement of loss angle in a dielectric 

(z) Spectrum Analyzer    (iv) Measurement of insulation resistance

Choose the correct option