Final answer:
A person who tries but fails to commit a crime is guilty of 'D) attempt to commit a crime,' involving intent and taking substantial steps toward committing the crime.
Step-by-step explanation:
Every person who attempts to commit any crime but fails or is prevented is guilty of D) attempt to commit a crime. An attempt to commit a crime involves the intention to commit a crime and taking some direct action towards its commission, but ultimately failing to complete it or being intercepted in the process. This is distinct from a conspiracy, which involves an agreement between two or more persons to commit a crime; solicitation, where someone urges another to commit a crime; and accomplice liability, where someone aids or encourages the principal offender.
It's important to consider the elements that must be present for a guilty attempt conviction: intent to commit the crime and a substantial step towards its commission. For example, purchasing materials to use in a robbery might be considered a substantial step. However, merely discussing or planning without taking a physical step is not enough to constitute an attempt.