Which one is the best paraprasing sentince

Companies that do business abroad sometimes find some local business practices, such as offering gifts or awarding contracts and privileges to family members, unethical. Source: Karl Smith, $2008,$ The ethical dilemma in business gifts: Giving or bribery? $$ A$.$ For many international firms, doing business overseas is unethical given the prevalence of practices, such as offering gifts $($K$.$ Smith, $2008).$ B$.$ According to Karl Smith, international companies are reluctant to invest abroad given the risk of unethical local market practices. O C$.$ Customs, such as bribery and nepotism, are perceived as corrupt by international firms doing business overseas $($Smith$,2008).$ O D$.($Karl$,2008)$ stated that companies interested in business abroad face many challenges.