Ethyl bromide reacts with lead-sodium alloy to form

The reaction, when ethyl bromide reacts with lead-sodium alloy to form Tetraethyl lead. 

TEL, or tetraethyllead, is an organ lead chemical. It is a fuel additive that was initially blended with gasoline in the 1920s as a patented octane rating booster that allowed engine compression to be significantly increased.
Bromoethane, often known as ethyl bromide, is a haloalkanes chemical compound. Chemists refer to it as $\mathrm{EtBr}$. The odor of this volatile chemical is similar to that of ether.

Hence, the correct answer is option (A) Tetraethyl lead