Answer:
He should request type O on his dating survey.
Opine's blood type must be AO to have a higher probability of producing O offsprings.
Step-by-step explanation:
O blood type is recessive so, when it is paired with another blood type like B or A, these would be dominant, giving B and A blood, respectively.
O blood type results are possible thanks to OO genotypes.
If the man's blood type is A, to have a higher chance of producing OO offsprings, his blood should be AO. The other possibility is that he has AA blood, which will result in a low probability of OO offsprings.
As regards the mother, her blood type should be OO.
We can see this more clearly in Punnet Square.
║ A ║O
O║AO║OO
O║AO║OO
There is a 50% of probability of having O offsprings with AO and OO.
║ A ║A
O║AO║AO
O║AO║AO
With AA and OO, the probability is 0%
║ A ║O
A║AA║AO
O║AO║OO
With both parents having AO, blood the probability of having a OO offspring is 25%.
In conclusion, the higher chances of producing a OO offspring is if the parents are AO and OO.