Final answer:
The dominant trait in the given options is straight hair. Hence the correct answer is option 1
Step-by-step explanation:
In the given options, the dominant trait is straight hair. Dominant traits are phenotypes that are expressed in both homozygous (AA) and heterozygous (Aa) genotypes. For example, if a person has one allele for straight hair (dominant allele) and one for curly hair (recessive allele), they will have straight hair because the dominant trait of straight hair hides the recessive trait of curly hair.
Hence the correct answer is option 1