How would you best describe the texture of an igneous rock that formed extremely slowly underground? question 7 options: ?

6. pegmatitic (a pegmatite is a very coarse-grained intrusive igneous ) 
rock 

7. shallow sea (limestone is the most common cemical sed rock, and they are most commonly in shallow marine environments) 

8. sunlight (wind, water and ice are the primary mechanisms for the breakdown and transport of rocks and their erosional products) 

9. addition of heat and pressure (heat through contact metamorphism with an igneous mass or by compression and deep burial, and pressure through tectonic forces) 

10. a different metamorphic rock (this sounds like a trick question. The use of "additional pressure" implies that pressure has already been applied, in which case a metamorphic rock has already formed. Therefore, a "different metamorphic rock" will result) 

11. stratification (strata are sedimentary layers) 

12. sedimentary (a conglomerate) 

13. extrusive (lavas have formed by "extrusion" from a volcanic edifice 

14. organic (includes coal and limestone) 

15. it will fizz in acid. (marble still is made up of calcium carbonate, which is the chemical which reacts with acid and fizzes)

The answer is a because - is an direction