for decades, countries have measured wheat field productivity using th

Let me explain this to you.

For decades, countries have measured wheat field productivity using the Wheat Field Productivity Index (WFPI), which is equal to the average number of pounds of grain harvested per acre of wheat. In 2005, Mlatnia's WFPI was 60 pound per acre more than Italy's WFPI. In 2006, Maltania's WFPI was 75 pound per acre more than Italy's. Therefore, Malania's wheat field productivity must have increased during that period.

Which of the following, IF TRUE, provides strongest support for the conclusion above?

A. Between 2005 and 2006, the number of acres of wheat planted in both Maltania and Italy has increased by same rate.
B. In 2006, Malatania received 20% more sunshine than usual.
C. Between 2005 and 2006, Italy's wheat field productivity decreased by 10 pound per acre.
D. In 2006, Italy experienced its worst drought in decades,
E. In 2006, Malatania began subsidizing all of its wheat farmer.

Explanation : In the argument presented, the conclusion is that Maltania's WFPI increased during the period from 2005 to 2006. We need to find the statement that strengthens the conclusion. Now, look at the figures mentioned in the argument closely. In 2005, Maltania's WFPI was 60 pound/acre more than that of Italy.
In 2006, the difference grew bigger with Maltania's WFPI 75 pound/acre more than that of Italy.

Let us now look at the answer choice C first. It says that Italy's WFPI actually decreased by 10 pound/acre.
But if you notice the difference in the increase from 2005 and 2006, it is 15 pound/acre. So, if Italy's WFPI decreased by 10 pound/acre, so if WFPI of
maltania remained the same, the difference would have been 70 pound/acre. But as per the argument, it is 75 pound/acre. So, for that to happen, the WFPI
of maltania has to increase.

Thanks !
Pass on Kudos please if you like my response !