Z with Intention to Steal Ornaments Opened Y's Box and Found

Multiple Choice

Z with intention to steal ornaments opened Y's box and found it empty. Which one of the following statements is correct? Z is:

A) Not liable for attempt to commit theft as the box being empty, commission of theft was impossible
B) Not liable for attempt to commit theft as he did not do the penultimate act towards commission of theft
C) Not guilty of attempt to commit theft as he made only preparation to commit theft
D) Guilty of attempt to commit theft as he had an intention to commit theft and did an act towards.