The music the medieval monks sang was called

a. contemporary gospel.
b. gregorian chant.
c. estampies.
d. trouvère songs.

B. Gregorian chant.

Explanation:

    Gregorian chant is the liturgical chant established by Pope St. Gregory the Great in the 6th century, adopted by the Catholic Church as an official chant, of an introspective and meditative character, that is why it was so practiced in conventual orders.

   As Christianity at that time came to dominate the main centers where the arts flourished, music was no different. Thus, official sacred music, so to speak, was Gregorian chant and, secondly, unofficial, profane music. This type of music called popular was despised by the followers of Gregorian chant, as it was seen as music that brought negative effects to the soul as opposed to the “elevated” music, which led the human being to something superior.

they are often in theme and variations