Which sentence from the passage is the best example of the author's attempt to develop interest and engage his audience?
a) glass also forms naturally when lava bursts from a volcano and then cools.
b) it would then make sense that a natural byproduct of the fiery volcanic explosions is a glass formation called obsidian.
c) at one time or another, we have all pressed our hands against a window and looked through a pane of glass to view the world
d) whether formed naturally or through manufacturing, the most common way of making glass is to superheat silica or quartzite sand to its melting point.