Crowdsourcing is:

a$.$ a classification of software that monitors trends among customers and uses this data to personalize an individual customer's experience.

b$.$ a phenomenon whereby firms can make money by offering a near$-$limitless selection.

c$.$ the removal of an organization from a firm's distribution channel.

d$.$ the act of taking a job traditionally performed by a designated agent and contracting it out to an undefined generally large group of people in the form of an open call.

e$.$ an industry practice whereby content is available to a given distribution channel for a specified time period or 'window,$\text{'}$ usually under a different revenue model.