The correct option is C 2008
Surplus
Year 2005 ⇒ 49.2−46.1=3.1 million tons
Year 2006 ⇒ 49.8−49.2=0.6 million tons
Year 2007 ⇒ 51.8−50.7=1.1 million tons
Year 2008 ⇒ 52.1−51.6=0.5 million tons
Year 2009 ⇒ 59.2−54.7=4.5 million tons
Year 2010 ⇒ 58.4−57.8=0.6 million tons
Hence, the surplus of cement was lowest for the year 2008.