Twenty eight mg equal to what

2.8 × 10-5 kilogram

...

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.

yes, because even though a theory has a  lot of evidence to support it, it is not always true