During striated muscle contraction, the a. actin and myosin become farther apart
b. Z-lines become farther apart
c. actin and myosin become closer together
d. Z-lines become closer together

i am going to guess that it is co2.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.