<span>C. nitrogen and hydrogen shoould be your answer
</span>
Answer: It is an amino acid that cannot be made by the body. It must be obtained from eating certain foods.
Explanation:
You need two recessive alleles (xx). If even one dominant allele is present, the dominant trait will show (Xx or XX will both result in the dominant trait showing). That’s why they’re called dominant traits, because they overpower the recessive traits. In order for a recessive trait to show you must have two recessive alleles.