The recommendations of the 12th Finance Commission cover a specific period of time. Option 1 suggests that the period covered is from 2004 to 2009. Option 2 suggests that the period covered is from 2005 to 2010. Option 3 suggests that the period covered is from 2006 to 2011. Option 4 suggests that the period covered is from 2007 to 2012.

By examining these options, we can deduce that the correct answer is option 2, which states that the period covered by the recommendations of the 12th Finance Commission is from 2005 to 2010. It is important to note that the Finance Commission is established every five years, and its recommendations for financial allocation and distribution are applicable for that particular five-year period.

This means that the 12th Finance Commission was in operation from 2005 to 2010, and its recommendations were formulated and implemented during this period.