Javier developed an idea for a software program to help perform real estate appraisals more quickly and accurately. He has worked with a buddy who is good at programming to develop a detailed description of what the software will do and how it differs from existing applications. Now Javier has taken this description and shown it to a number of fellow real estate agents to see if his idea appeals to them. Javier is engaging in

Multiple Choice

$$ prototype outsourcing

$$ B$2$B advertising

$$ concept testing.

$$ word$-$of$-$mouth promotion.