Had a couple of questions about Y seat selection on two flights on AC 77W (2-class) and 77L.

1) Can Tango fares choose seats in rows 21-24 on 77W?

2) Can Flex fares choose seats in rows 20-23 on 77L?

I can't choose seats on AC website and have to call them, so I thought I will ask this here before calling AC so I know if I am allowed to choose seats in these rows.

Thanks.