What is the difference between illegal behaviour and unethical behaviour?

a$.$ What is illegal varies from country to country, but what is unethical does not.

b$.$ There is no real difference between illegal and unethical behaviour.

c$.$ Illegal behaviour covers a broader range of issues than unethical behaviour.

d$.$ It is not possible to say what the difference is between illegal and unethical behaviour.

e$.$ Illegal behaviour is that which breaks a country's laws, but unethical behaviour may not break any laws.