Genotype-phenotype concept was first proposed by
A.Bateson – He coined the term Genetics.
B.Johannsen – He first proposed the Genotype-phenotype concept.
C.Sutton & Boveri – They proposed the chromosomal theory of Inheritance.
D.Punnet – He introduced the Punnet-square method, It is used to understand the results of Mendel’s cross.
So, the correct option is ‘Johannsen’.