Many metamorphic rocks are found along the southwest border of mexico. what is a likely reason for this ?

The reason why there is an abundance of metamorphic rocks in the southwestern part of Mexico is the intense geologic activity in this area. In this area there is geologic activity triggered by the convergent plate boundary of the North American plate and the Cocos plate. The Cocos plate subducts bellow the North American plate, and that causes the surrounding crust to be exposed to high temperatures and pressures. Those high temperatures and pressure lead to metamorphism of the rocks that are deep into the crust. Also, the land is lifted up because of the subduction zone, so these metamorphic rocks start to emerge on the surface or very close to it because they have been pushed upwards.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.