Which of the following enhances or induces fusion of protoplasts?

• Sodium chloride and potassium chloride

• Polyethylene glycol and sodium nitrate

• IAA and kinetin

• IAA and gibberellins

B.

Polyethylene glycol and sodium nitrate

Polyethylene Glycol (PEG) and sodium nitrate enhances fusion of protoplasts (protoplast fusion). Protoplast fusion is a physical phenomenon which occurs due to the fusion of protoplast (cell without cell wall) of two or more cells. It can be done by mechanically (spontaneous) or inducing agents. 
(i) Spontaneous agents Mechanical fusion
(ii) Inducing agents (i) NaNO₃ treatment.
(iii) High pH or Ca²⁺ treatment.
(iv) PEG treatment
(v) Electrofusion.