Assume a system has the following requirement: "An outdoor meteorological unit, equipped with a 1000 milli-ampere hour cell, should be capable of supplying the power requirements of the unit for at least 30 days. The system performs measurements once per hour, logs the results, and transmits the results once a day to the meteorological center by means of wireless communication". This requirement is related to which of the following factors: Group of answer choices Efficiency Safety Security Reliability