Which method is commonly used in the layering stage of money laundering?

The layering stage of money laundering is characterized by the process of obscuring the origins of illicit money through a series of complex transactions. This is done to make it difficult for authorities to trace the illicit funds back to their original source. Transferring money across multiple accounts is a hallmark of this stage, as it involves moving funds between different banks, sometimes across borders. This creates a confusing trail of transactions that can effectively disguise the money's origins.

In contrast, depositing cash directly into one account is more aligned with the placement stage, where the goal is to introduce illicit money into the financial system. Investing in real estate could occur later but is typically part of integration rather than layering. Holding money in physical cash does not create the necessary complexity to obscure the money's origins effectively. Thus, transferring money across multiple accounts serves as an essential tactic in the layering phase, making it the most accurate choice for this question.