How do i do the calculations for this?

On 1 July 2012 Lancashire Ltd grants 100 share options to each of its 50 employees conditional upon the employee working for the entity for the next 3 years. On the same date, the entity estimates the fair value of each share option at $15. Based on probability estimates, 15 employees are expected to leave the entity in one year and another 5 employees in two years. Actual resignation for the year ending 2013 was 12 employees and the fair value of the option is $12 on 30 June 2014.

In accordance with AASB 2, what is the cumulative remuneration expense (related to the share option issue) as at 30 June 2011?

A.

$24 000

B.

$26 400

C.

$33 000

D.

$45 000