I believe the answer is C, Sedimentary rock.
Hope this helps.
Closed complex formation, open complex formation, start of RNA synthesis, promoter clearance
Answer: Bull's genotype: RW
Cow's genotype: WW
50% are roan color
50% are white color
Explanation:
A cross between a heterozygous roan bull (RW) and a homozygous white cow (WW), will yield 50% roan and 50% white offsprings.
See the attached punnet square for illustration