Detailed Instructions: This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
Q: Passage: Chengdu Economic and Technological Development Zone (Chinese: ; pinyin: Chengdu jingji jishu kaifa qu) was approved as state-level development zone in February 2000. The zone now has a developed area of 10.25 km2 (3.96 sq mi) and has a planned area of 26 km2 (10 sq mi). Chengdu Economic and Technological Development Zone (CETDZ) lies 13.6 km (8.5 mi) east of Chengdu, the capital city of Sichuan Province and the hub of transportation and communication in southwest China. The zone has attracted investors and developers from more than 20 countries to carry out their projects there. Industries encouraged in the zone include mechanical, electronic, new building materials, medicine and food processing.
A:
What was approved as a national-level development zone in 2000?