Answer:
A. q 0.55
Explanation:
Frequency of genotye "BB" [tex]= \frac{2}{10}[/tex][tex]=0.2[/tex]
Frequency of genotye "bb" [tex]= \frac{3}{10}[/tex][tex]=0.3[/tex]
Frequency of genotye "Bb" [tex]= \frac{10-(2+3)}{10}[/tex][tex]=0.5[/tex]
Frequency of bb is represented as "[tex]q^{2}[/tex]" as per Hardy Weinberg's principle.
Thus, frequency q of the recessive allele b is represented by
[tex]q= \sqrt{q^{2} } \\q = \sqrt{0.3} \\q = 0.547\\q=0.55[/tex]
Hence, option A is correct.