The passage suggests that the presence of G10 garnet in a kimberlite pipe indicates that:. (A) the pipe in which the garnet is found has a 90% chance of containing diamonds
(B) the levels of calcium and chrome in the pipe are conducive to diamond formation
(C) the pipe passed through a diamond-stability field and thus may contain diamonds
(D) any diamonds the pipe contains would not have come from the diamond-stability field
(E) the pipe's temperature was so high that it oxidized any diamonds the pipe might have contained

Correct

(C) the pipe passed through a diamond-stability field and thus may contain diamonds

Explanation:

The passage from which the question was gotten is attached below:

Diamonds are almost impossible to detect directly

Diamonds are almost impossible to detect directly because they  are so rare: very rich kimberlite  Line pipes, the routes through which  diamonds rise, may contain only  three carats of diamonds per ton  of kimberlite. Kimberlite begins as  magma in Earth's mantle (the layer  between the crust and the core).

As   the magma smashes through layers  of rock, it rips out debris, creating  a mix of liquid and solid material.  Some of the solid material it brings  up may come from a so-called  diamond-stability field, where conditions of pressure and temperature  are conducive to the formation of diamonds.

If diamonds are to survive, though, they must shoot toward  Earth's surface quickly. Otherwise,  they revert to graphite or burn.  Explorers seeking diamonds look  for specks of indicator minerals.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)