What is the best source of information for deciding whether a product meets your needs? the product's advertisements the product's brand name the product's label

The best source of information would be the products label.

The product's advertisement could give you misleading information. Advertisements are meant to sell the products without actually telling you much about the product. The brand name is just a name and tells you what the product is called that is it. The label itself will have information on it about what the product is and what is in it.