GWD-18-Q31中it的指代问题

Between 1990 and 2000the global economy grew more than it did during the 10,000 years from the beginningof agricultureto 1950.
A. Between 1990 and 2000 the global economy grew more than it did duringthe 10,000 years from the beginning of agriculture
B. Between 1990 and 2000 the growth of the global economy was more thanthat during 10,000 years, from when agriculture began
C. The growth of the global economy between 1990 and 2000 exceeds thatwhich had been for 10,000 years from the beginning of agriculture
D. The growth of the globaleconomy between 1990 and 2000 exceeds what it has been for 10,000 years, fromwhen agriculture began (A)
E. The growth of the global economy between 1990 and 2000 exceeded what itdid for the 10,000 years from the beginning of agriculture

选项分析：A. Correct；it完全指代the global economy，并不特指1990到2000年之间的global economy
B. the growth of sth. was不如sth. grew简洁；from when agriculturebegan to 1950的不如from the beginning ofagriculture to 1950好（另有一待验证说法：from when错误，when前面接介词awkward）；that指代错误，无法指代the growth of the globaleconomy整个短语，只能指代growth；from when做非限定性修饰错误；应该用during the 1000 years来特指那1000年
C. that which had been用法awkward，时态错误（一般过去时即可），且that指代错误，无法指代the growth of the globaleconomy整个短语，只能指代growth；for 1000 years错误，应该在1000 years前加上定冠词以特指那1000年；exceeds时态错误，应该用一般过去时（比如Shakespears was anEnglish poet.也用一般过去时）
D. exceeds时态错误，应该用一般过去时；it指代the growth of the globaleconomy between 1990 and 2000错误；现在完成时使用错误，应改为过去时态(一般过去时或过去完成时)；for 1000 years错误，应该在1000 years前加上定冠词以特指那1000年；from when做非限定性修饰语义错误
E. it指代the growth of the globaleconomy between 1990 and 2000错误；what it did含义错误，growth不会做任何事情；did没有所指代的动词

为什么a选项中的it就不指代the growth of the global economy between 1990 and 2000？难道只是因为between 1990and2000的位置不一样吗？