Errol, in His Home-Made Will, Leaves 'Ten of My Most

Errol, in his home-made will, leaves 'ten of my most precious pieces of crystal' to be held by Jonathan, his trustee, 'in the expectation that he will distribute them to such of such students who graduated in 2015 from Barchester University as Jonathan in his absolute discretion shall decide.'
Jonathan has been diagnosed as suffering from dementia and is incapable of making a decision.
Which of the following statements is correct?

A) The trust fails and the crystal forms part of Errol's residuary estate.
B) The trust fails and the crystal forms part of Jonathan's personal assets.
C) There is still a trust, but because Jonathan cannot make a decision, the crystal must be divided equally between the whole graduating class.
D) There is still a trust, but because Jonathan cannot make a decision, a new trustee can be appointed by the person authorised to make such an appointment, or by the court, and that trustee can make a decision.