The option price is probably in line with most options that companies offer - circa 15-20% below market price, exercisable 3 years later. Clearly the incentive is for the directors to make plans and strategies that see the actual share price rise way ahead of the option price, therefore not only netting the directors a good profit but also the general share holders. Options are a great way of tieing in good directors and ensuring that they only benefit if the company does well - remember they get nought if they leave before the exercisable date. The directors will not be happy with the share price still being around 12p in 3 years as they would pocket very little after tax, inflation etc.
As a holder I think the options should be good for DNX, although it may be a medium to long term benefit