Isaac is the CEO of a small start-up. He and two of his friends were working in an environment with lots of young people and noticed a trend. Young people seemed to use their smartphones as mini-computers, and many of them purchased "flip phones" to make actual phone calls. So, Joe and his friends decided to create bags that had holders for these two phones. They talked to some of these young people and felt pretty good about the potential for their business to succeed. They invested their savings, and countless hours over the past year, into creating the bag and marketing it to these young dual phone users. However, they have only sold two. Recently, one of Isaac's business partners suggested that maybe, in addition to the bag, they could create flip phone covers to make the flip phones more interesting to carry. So they have started to invest in this.

Which of the following biases best describes why Joe and his colleagues are continuing to invest in this business?

A.Representativeness bias

B.Status quo bias

C.Anchoring

D.Escalation to commitment

E.Availability bias