The answer is B. a nucleus.
Prokaryotic cells do not have a nucleus. They have ribosomes, a cell membrane, a cell wall, and DNA, but lack a nucleus. Prokaryotes also don't have mitochondria or chloroplasts and generally lack organelles.
I have no idea what that means but the answer is b
as insects became exposed to pyrethroids, toxicity of pyrethroids weakened over time. which means that Most insects had the allele for pyrethroid resistance, but it remained masked. The allele for said pyrethroid resistance, evidently increased throughout the population.
has this helped?