in a high emissions scenario how much do scientists predict the Earth will heat up by the end of the century, compared with the average temperature between 1986 and 2005

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.

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.