Answer:
Option d: Retrieval failure
Step-by-step explanation:
Forgetting simply known as the inability to retrieve former (previously) saved (stored) information from long term memory.
Retrieval failure is a form or type of forgetting.it is also called Cue-dependent forgetting. It occurs when we don't have the compulsory (necessary) cues to access memory. That is memory is said to be in place (available) but not readily accessible unless a suitable cue is provided.
Retrieval Failure Theory simply suggests that forgetting happens due to the fact that we lack or fail to use the right cues to locate/recover information stored in memory.