In His Second Year of Managing the Accounting Department, Drew

In his second year of managing the accounting department, Drew set a goal for his team to slightly improve its "days billing" from last year's mediocre 36 days to 35.5 days. Midway through the year, Drew is disappointed that the "days billing" has actually worsened, to 37 days. Drew's manager advised Drew that, to motivate his staff to perform at a higher level, Drew should set a goal that is

A) unattainable.
B) subjective.
C) provisional.
D) not quantifiable.
E) more challenging.