Prodeff, an online project management software, is available at a price of $1 per use. The software requires the user to enter the initiation date, the number of resources, the time allotted to each resource, the cost per resource, and the number of tasks in the project. Based on the input provided by the user, the software determines the duration of the task and the total cost of the project. In this scenario, the cost incurred by users while using Prodeff is the _____. a. communication cost b. acquisition cost c. processing cost d. retrieval cost