What was one of the major theological concerns addressed in canto iv?

One of the major theological concerns that were addressed in Canto IV was the problem of what would happen to infants who died unbaptized.

Canto IV is part of Inferno by Dante Alighieri and is settled in Limbo, where virtuous non-Christians and unbaptized children go.

Inferno is the first part of Italian writer Dante Alighieri's 14th-century epic poem Divine Comedy. It is followed by Purgatorio and Paradiso. The Inferno tells the journey of Dante through Hell, guided by the ancient Roman poet Virgil.