Which one of the following is formed by adding -ing to the base form? a- the present participle b- the past tense c- the present (base form) d- the past participle

How does woodrow wilson make his central idea more persuasive? he argues that free trade and unrestricted commerce is the best way to ensure peace, he argues that the german people want peac and would welcome us intervention. he claims that the united states is now a major power and must restore peace, he concludes by arguing that only war can ensure others the peace and freedom that americans enjoy the answer is d. he concludes by arguing