Final answer:
DOCSIS 3.0 included the option to increase the tap frequency of the upstream to 85 MHz, enhancing upstream performance for cable systems.
Step-by-step explanation:
The version of the DOCSIS specification that included the option to increase the tap frequency of the upstream to 85 MHz was DOCSIS 3.0. This enhancement was introduced to allow for better upstream performance and to support a wider range of services. DOCSIS, which stands for Data Over Cable Service Interface Specification, is the international telecommunications standard that permits the addition of high-bandwidth data transfer to an existing cable TV system.