In the hexaploid wheat, the haploid ($$n$$) and basic ($$x$$) numbers of chromosomes are
n=21 and x=21
n=21 and x=14
n=21 and x=7
n=7 and x=21
The correct option is B $$n=21$$ and $$x=7$$ Ploidy level is the number of complete sets of chromosomes in a cell. Wheat is hexaploid which is denoted as 6x and has 42 chromosomes, here ' x' is the basic number of chromosomes, they are the different chromosomes which makes up a single complete set of chromosomes which is 7 in case of wheat while ' n ' is referred to as the haploid number of chromosomes i.e; half the total number of chromosomes which is 21 in wheat .