Final answer:
In Alberta, the caribou is the member of the deer family that is protected year-round due to its vulnerable status and the need for significant fat reserves to survive winter conditions.
Step-by-step explanation:
The member of the deer family that is protected year-round in Alberta is C. Caribou. This is because caribou populations are considered vulnerable or threatened in various regions, including Alberta. Their survival is at risk due to factors such as habitat loss, climate change, and human disturbances. Caribou require a significant amount of stored energy in the form of fat to survive the harsh winter conditions, as they release more energy during this period. Therefore, consistent protection is necessary to help maintain their populations and ensure their continued existence in the wild.