Saje Natural Wellness has experienced tremendous growth and knows that to sustain such growth they must continue to deliver high-quality products with outstanding customer service. To this end their strategic objective for 2020 is to invest in sales staff training. With 50 locations across North America, they have decided that this can be best executed by hiring a Director of Customer Experience who will create online instructional videos for staff that can be viewed multiple times at store level to build the kind of quality staff they desire for the customer experience they want to create and sustain. They are investing in staff training to deal with which service characteristic? a. heterogeneity b. intangibility c. inconsistency d. perishability