The correct option is A This is because foreign powers controlled the economy of China, though the Chinese Emperor still administered the empire till 1911.
China had to give up a lot at the conclusion of the Opium Wars - except for its ruling rights. It had to pay a heavy war indemnity. In addition to this, they had to give free trading rights to English, and keep import duties to the minimum. The French, the German, the Russians, and the Japanese followed in the later years, claiming their own areas of influence.
Although the Chinese Emperor still administered the empire till 1911, its economy was controlled by the foreign powers. Hence, China can be considered as semi-colony and not a full-fledged colony of any particular country.