Final answer:
Lomov and Natalya's first argument is about the ownership of the Oxen Meadows, which is a dispute related to their family inheritance.
Step-by-step explanation:
The first topic that Lomov and Natalya argue about in the play is c) Who owns the Oxen Meadows. This argument begins as a disagreement over the ownership of a piece of land known as the Oxen Meadows, which both parties claim as part of their family inheritance. The contention over whether the meadows should be considered part of Natalya's family inheritance, which is supposedly greater, sets off a series of arguments that form the basis of the comedic conflict in the play.