Final answer:
The memory function involved in texting your roommate's number upon request is working memory, which processes and holds information temporarily.
Step-by-step explanation:
The 'memory function' involved in responding to the request of 'please text me your roommate's number' would be D) Working memory. Working memory is a cognitive system that holds information temporarily available for processing. It is part of the brain's system for encoding, storing, and retrieving information. In the context of the request, you would first retrieve your roommate's number from long-term memory, and working memory would then maintain that information while you compose and send the text message.