$"$LSS: Stephanie over in Personnel is the coordinator of incoming job applications, some of which arrive by mail, some by fax, and some via the company's website. She's found it is more convenient if she waits until she has a stack of at least $25$ applications that she can log into the database all at once, rather than trying to do them as they come in$.$

What is the "thing" flowing in the process?"

And the possible answers are:

$-$ Job applications

$-$ Stephanie's utilization rate

$-$ Mail, fax, website

$-$ The wait time to let $25$ applications pile up