The power that has been deemed "necessary and proper" typically refers to powers that are not explicitly stated in the Constitution but are necessary to carry out the government's enumerated powers. Among the options provided, one example that is often discussed in this context is the power to institute a draft. The draft is derived from the federal government's power to raise and support armies, which is an enumerated power.
The other powers listed, such as punishing pirates, coining money, and levying taxes, are generally considered enumerated powers explicitly mentioned in the Constitution.