Police chief: During my tenure as chief, crime in this city has fallen by 20 percent. This is clearly the result of m...

The chief only said the officers in the precinct have never taken it. That's a fraction of the people of a precinct, which could plausibly have receptionists, sergeants, 911 operators, lieutenants, etc. That's a limited sample of all the people (employees) in the precinct who could have grafted. Why is A wrong?