The correct answer is: A. Sodium
Sodium is a very reactive metal that is kept in kerosene to prevent it from reacting with water and oxygen in the air. When sodium comes into contact with water, it reacts violently to form sodium hydroxide and hydrogen gas. This reaction can be very dangerous, so it is important to keep sodium away from water.
Potassium is also a very reactive metal, but it is not as reactive as sodium. Potassium is also kept in kerosene to prevent it from reacting with water and oxygen in the air. However, potassium is not as dangerous as sodium, and it can be handled more safely.
Iodine is a non-metal that is not as reactive as sodium or potassium. Iodine is not kept in kerosene, but it is often stored in dark bottles to prevent it from being exposed
to light. Light can cause iodine to decompose, so it is important to store it in a dark place.Bromine is a non-metal that is more reactive than iodine. Bromine is kept in a sealed container to prevent it from reacting with the air. Bromine is a liquid at room temperature, and it can be very dangerous if it is exposed to heat or flame.
In conclusion, the correct answer is: A. Sodium. Sodium is a very reactive metal that is kept in kerosene to prevent it from reacting with water and oxygen in the air.