What Would Be a Tertiary Prevention Measure Implemented by the CHN

What would be a tertiary prevention measure implemented by the CHN to prevent TB?

A) Administering a purified protein derivative (PPD) to the contacts of those infected with TB
B) Initiating directly observed therapy (DOT) for TB-positive clients
C) Providing education about the prevention of TB to members of the community
D) Using skin tests to screen all health workers for TB