Final answer:
The attributive phrase in the provided sentence is 'Silicon memory,' which modifies 'recall' to specify the type of memory. Contrarily, a 'flashbulb memory' refers to a vivid recollection of an emotionally significant event, and an 'engram' is the hypothesized physical trace of a memory.
Step-by-step explanation:
The attributive phrase in the sentence "The perfect recall of silicon memory" wired Clive Thompson has written, can be an enormous boon to thinking?" is c) Silicon memory. This phrase modifies "recall" and specifies the type of memory being referred to. In contrast, flashbulb memory is a vivid and detailed memory of an emotionally significant event, which can be considered an example of a perfect recall but is not the attributive phrase in this context. Meanwhile, an engram is a theoretical concept representing the physical trace of memory in the brain.