Under which regulation is the power to issue subpoenas to appear before a board granted?

The correct regulation that grants the power to issue subpoenas to appear before a board is found in 8 CFR 287.4A. This regulation specifically outlines the authorities of the immigration enforcement processes, including the ability of the Immigration and Customs Enforcement (ICE) to summon individuals for investigative purposes.

The importance of this regulation lies in its role in ensuring that immigration proceedings can be conducted fairly and thoroughly. By granting the power to issue subpoenas, it allows for the collection of evidence and testimony that may be crucial to the determination of immigration cases. Subpoenas serve as a legal tool to require individuals to appear or produce documents, thereby enhancing the integrity of the enforcement process.

In contrast, the other options, while related to immigration law, do not specifically address the power to issue subpoenas. Therefore, the correct answer reflects the appropriate regulation that explicitly provides for this authority in the context of border patrol and immigration proceedings.