What is correct Deal in or deal with?

The phrase "deal with" is commonly used to refer to handling or addressing a situation, issue, or person. For example, you might say, "I need to deal with this problem." On the other hand, "deal in" refers to engaging in the trade or business of a specific item or commodity, such as "They deal in antique furniture." Thus, the correct phrase depends on the context of what you want to convey.