The MOST likely reason they made this decision is that:

A global financial institution has decided not to take any further action on a denial of service (DoS) risk found by the risk assessment team. The MOST likely reason they made this decision is that:

A.
thereare sufficient safeguards in place to prevent this risk from happening.

B.
the needed countermeasure is too complicated to deploy.

C.
the cost of countermeasure outweighs the value of the asset and potential loss.

D.
The likelihood of the risk occurring is unknown.

Explanation:
An organization may decide to live with specific risks because it would cost more to protect themselves than the value of the potential loss. The safeguards need to match the risk level. While countermeasures could be too complicated to deploy, this is not the most compelling reason. It is unlikely that a global financial institution would not be exposed to such attacks and the frequency could not be predicted.