According to CDC Guidelines,what Should Be Done First If a Vaccinated

According to CDC guidelines,what should be done first if a vaccinated health care worker sustains a needlestick or puncture wound involving exposure to blood from a patient known to be HBsAg-positive?

A) Nothing, because the health care worker has already been vaccinated.
B) The health care worker should be tested for an adequate titer of anti-HBs if those levels are unknown.
C) The health care worker should immediately receive an injection of HBIG.
D) The health care worker should immediately receive an injection of the hepatitis B vaccine as a booster dose.