The correct answer is C. Brethren.
Brethren is the plural form of brother. It is a word that is used to refer to a group of people who are united by a common bond, such as religion, profession, or social status.
The word brethren is derived from the Old English word brÄðor, which means “brother.” The word brÄðor is itself derived from the Proto-Indo-European word *bhrÄter, which also means “brother.”
The word brethren is first attested in the Old English poem Beowulf, which was written in the 8th century. The word is also used in the King James Bible, which was published in 1611.
The word brethren is still used today, although it is not as common as it once was. It is often used in religious contexts, such as when referring to a group of monks or nuns. It can also be used in a more general sense to refer to a group of people who are united by a common bond.
The other options are incorrect because they are not the plural form of brother. The word brethron is not a word in the English language. The words brethoren and Brothren are misspellings of the word brethren.