The correct option is D time
There are various types of utility such as time, form, service, possession, knowledge & place utility. Changing the time of utilization leads to time utility. It occurs when the use of commodity defers for future use in case of emergency. It is derived by keeping or storing the commodity from the time of procurement or production to the time of consumption. Here there will always be a time gap between the procurement and consumption. Blood donation has time utility as donated blood is stored for to be used later on in case of emergency.