Yep seem like the website a problem with creating poll.
The choice was:-
Your two dual threats would be Sentinel and Red Skull. Zola is the best defender of the group. Jack and Prowler are attackers. Shuri is long form content, Warlock is your regen/power gain counter.
These questions are difficult because each champ does something different. Since you have Ironheart (attacker), I'd go with Zola, then Sentinel, then RS.