Out of these 4 items which 2 would you use on irelia

hmm it depends ... what are you playing against are you ahead or behind?

Steraks is usually a good item since it synergizes well with MAW is good against heavy AP matchups Yomuu's would be pretty meh in most situations unless you were building to assassinate a high priority target. BOTRK is good against tanks. For instance

none are inherently better than the others, except yomuus which is sub par on her.

BOTRK and situationally Maw.

Sterak's Gage > Maw > Ruined King > Youmuus.

If the enemy team's AP damage threat is very low

Sterak's Gage > Ruined King > Maw > Youmuus

If no AP on the enemy team

Sterak's Gage > Ruined King > Youmuus > Maw