Do-It-Yourself Defined Contribution Plan Owns the Following Assets with the Following

Do-it-Yourself Defined Contribution Plan owns the following assets with the following values: $$\begin{array} { | l | l | l | } \hline & 30 \text { June 2012 } & 30 \text { June 2013 } \\\hline \text { Land } & \$ 200000 & \$ 240000 \\\hline \text { Buildings } & 150000 & 170000 \\\hline \text { Property, plant and equipment } & 50000 & 40000 \\\hline \text { Motor vehicles } & 60000 & - \\\hline \text { Investments in listed securities } & 110000 & 130000 \\\hline \text { TOTAL } & \$ 570000 & 580000 \\\hline\end{array}$$ The fund sold its motor vehicles for $70 000.
What amount of revenue for changes in net market value of assets should Do-it-Yourself Defined Contribution Plan recognise for the year ended 30 June 2013?

A) $10 000
B) $20 000
C) $50 000
D) $80 000