What can you conclude about the crystals in image a relative to the crystals in image b?

select one:
a. the crystals in image a had more room to grow than the crystals in image b.
b. the crystals in image a were formed over a shorter period of time than the crystals in image b.
c. unlike the crystals in image b, the crystals in image a were cut into the rock by humans.
d. unlike the crystals in image b, the crystals in image a were formed in a water-based solution.