The correct option is CHINA AND THE COUNTRIES WITH SPHERES OF INFLUENCE.
The open door policy is used to refer to the US policy which was established in the late 19th century. The policy proposed to keep the Chinese market open for all and not allow anyone country to gain control over the country. The major aim of the policy was to enable the US to trade with the Chinese. John Hay was the secretary of state during that period and he was the one who wrote the open door note.
