A person would not drown in the dead sea or a salty lake even if the person does not know how to swim. This is due to :

The correct option is high density of sea water.

Explanation:

The Dead Sea has an extremely high concentration of dissolved salts and minerals compared to normal ocean water. Because of this large amount of dissolved salt, the density of the water increases significantly.

According to Archimedes' principle, an object or person floats when their average density is less than the density of the fluid surrounding them. Since the average density of the human body is around:

$985\text{kg/m}\sqrt[]{}3$

to

$1000\text{kg/m}3$

and the density of the Dead Sea water is approximately:

$1240\text{kg/m}3$

the water exerts a massive upward buoyant force on the human body. Because the high density of the sea water causes the buoyant force to easily exceed the body's downward gravitational force, a person naturally floats on the surface without needing to swim.