Answer:
a) his irritation with the isolationists.
Explanation:
President Franklin Roosevelt's goal upon entering office in 1933 was the American economy and combating the ills of the Great Depression. This actually triggered him to formulate American laws and policy inorder to actualise that. In the course of his time, the isolationists in his government tried to limit his foreign policies by passing series of laws like the Neutrality Acts of 1935 , 1936 and 1937 which restrict selling of weapons to countries at war and preventing Americans from travelling on ships belonging to countries engaged in wars.
His growing irritation with the isolationists when his aim has been to strengthen ties with foreign markets prompted him to change his foreign policy. This lead to the lifting of the ban on the Neurality Acts.