TECO Coal Corporation Mines and Ships More Than Six Million

TECO Coal Corporation mines and ships more than six million tons of coal annually.TECO is comprehensively regulated by the U.S.Bureau of Mines.The U.S.Bureau of Mines may conduct a surprise inspection of one of TECO's mines

A) only if it has a search warrant.
B) only if it has a subpoena.
C) only if it has reason to believe a violation of a regulation has occurred.
D) without a search warrant to ensure safety.