Banco Santander New York's main activities include which of the following?

Banco Santander New York's main activities include Treasury Derivative Trading. This means that the bank engages in the buying and selling of financial instruments, such as options, futures, and swaps, that are based on underlying assets like bonds, currencies, and commodities. This activity allows the bank to manage its own risk and provide services to clients who want to hedge their exposure to market fluctuations. Private banking and retail banking are not mentioned as main activities, so they are not included in the answer.