(a)→(ii) Sand Meyer reaction
(b)→(iv) Gatterman reaction
(c)→(i) Wurtz reaction
(d)→(iii) Fittig reaction
The Wurtz reaction is a very useful reaction in the fields of organic chemistry and organometallic chemistry for the formation of alkanes.
In this reaction, two different alkyl halides are coupled to yield a longer alkane chain with the help of sodium and dry ether solution.

