Answer: The correct answer is-
A) Dd.
Genotype can be described as the genetic makeup of an organism ( which is represented by gene variants that is alleles) that depicts particular morphological form ( trait) of the organism ( such as tall and dwarf plant height).
A dominant trait ( represented by capital letter allele such as 'D' for dimples) always masks the expression of recessive trait ( represented by small letter allele such as 'd' for no dimples).
As per the information given in this question, having dimples is a dominant trait.
Thus, if we inherit one dominant and one recessive allele, the genotype would be Dd ( that is heterozygous dominant).