What is an exculpatory clause?

a$)$ a provision that protects directors from personal liability to the corporation and its shareholders

b$)$ a provision that if a party enters into a contract believing in good faith that the corporation exists, he cannot later take advantage of the fact that it does not

c$)$ a requirement that the company pay the legal fees of directors who are sued for actions taken on behalf of the company

$$ d$)$ a requirement that a corporation cannot undertake any transaction unless the charter permits it