I think it is c but I’m not sure
Answer: Option (B) is the correct answer.
Explanation:
It is known that for writing a chemical reaction equation, reactants are written on left hand side whereas products are written on right hand side.
And in between reactants and products a forward arrow is placed pointing towards the products.
Therefore, the reaction for carbon burns in the presence of oxygen to give carbon dioxide will be written as follows.

Here, carbon and oxygen atoms are the reactants whereas carbon dioxide is the product.
Explanation:
if you post the whole question I can help you
The answer is dilute. A dilute salt solution contains a small amount of salt with high water concentration while a concentrated salt solution has a large amount of salt with a lower water concentration. Salt is inorganic hence it is not monounsaturated, which is a term related to organic compounds. The salt is unable to dissolve anymore in a saturated salt solution, leaving the undissolved salt at the bottom and this is not the case here since we only have a small amount of salt.