According to Harlow v. Fitzgerald government officials performing O a. mandatory functions are not shielded from liability for civil damages as long as their conduct does not violate clearly established statutory or constitutional rights of which a reasonable person would have known. O b. mandatory functions are shielded from liability for civil damages as long as their conduct violates clearly established statutory or constitutional rights of which a reasonable person would have known. O/c. discretionary functions are not shielded from liability for civil damages as long as their conduct does not violate clearly established statutory or constitutional rights of which a reasonable person would have known. O d. discretionary functions are shielded from liability for civil damages as long as their conduct does not violate clearly established statutory or constitutional rights of which a reasonable person would have known