The correct answer to this question is B. The term "smurf" is a colloquial term for a money launderer, derived from the small cartoon characters of the same name. By breaking up large amounts of money into smaller amounts, they are able to keep their transactions under a reporting threshold, or an amount subject to scrutiny.
These transfers can be done as cash deposits, money orders, prepaid gift cards, etc. Another strategy is to complete multiple transactions over a number of days. This process is often also outsourced to multiple third parties, including strangers, to further reduce the risk of being caught.