Final answer:
The key event that was instrumental to the evolution of computer forensics was the development of the Computer Analysis & Response Team (CART) in 1984.
Step-by-step explanation:
The event instrumental to the evolution of computer forensics was Option 3: 1984: Computer Analysis & Response Team (CART) was developed. This team's establishment marked a significant step forward in the field of computer forensics as it provided structured and systematic methods to analyze electronic data for legal purposes. The emergence of computer forensics resulted from a greater need to address crimes involving digital evidence as computers became more integrated into society for business, government, and personal use. The impact of CART's creation continues to resonate in today's digital age, where the preservation, identification, extraction, and documentation of computer evidence are critical for legal scrutiny and cybercrime investigation.