alex.gellatly wrote:The yield of natural gas from Norway's Troll gas field is expected to increase annually until the year 2005 and then to stabilize at six billion cubic feet a day, which will allow such an extraction rate at least for 50 years' production.

A. 2005 and then to stabilize at six billion cubic feet a day, which will allow such an extraction rate at least for
B. 2005 and then to stabilize at six billion cubic feet a day, an extraction rate that will allow at least
C. 2005 and then stabilizing at six billion cubic feet a day, with such an extraction rate at the least allowing
D. 2005, then stabilizing at six billion cubic feet a day, alloying such an extraction rate for at least
E. 2005, then stabilizing at six billion cubic feet a day, which will allow such an extraction rate for at least

alex.gellatly wrote:So, when you use which it can only refer to the noun right before it, not the whole noun phrase, right? That is why A and E are wrong. So we must use an extraction rate because in A we don't know what which is referring to.

Thanks everyone!