Answer:
Crossing the hygienic queen with hygienic drones.
Step-by-step explanation:
For producing hygienic workers (females) in the F2 generation, the hygienic queen must be cross with hygienic drones. Due to this crossing most of the offspring produced will be hygienic due to presence of dominant allele of hygienic. Both the male and the female bees have dominant allele of hygienic so the maximum number of offspring produced will be of hygienic and very low number of offspring is produced having unhygienic allele.