In plants, sex determination is due to

Plants follow XY mechanism of sex determination in which presence or absence of Y chromosome determines the sex of the plant. Irrespective of the ratio of the number of X chromosomes to set of autosomes, presence of Y chromosome determines the male sex of the plant. Chromosomes other than sex chromosomes are called autosomes and are represented by ?A?. As is evident from the independence of sex of plant to X/A ratio, A-chromosomes are not sex determinant. B chromosomes are the supernumerary chromosomes which are dispensable and do not play any role in sex determination. Thus, the correct answer is option B.