Final answer:
The board of directors generally signs the legal letter as they are responsible for the overall management and governance of the entity being audited.
Step-by-step explanation:
In general, the legal letter is signed by the board of directors of the entity being audited.
This is because the board of directors is responsible for the overall management and governance of the entity. They have the authority to make decisions on behalf of the entity and are therefore typically the ones who sign legal letters.
The audit partner, the CEO of the entity being audited, and the entity's attorneys may also sign legal letters in certain circumstances, but it is more common for the board of directors to do so.