Which battle saw Caesar defeat the forces commanded by Metellus Scipio?

The Battle of Thapsus, fought in 46 BC, was a significant conflict during the civil war in which Julius Caesar faced off against the forces commanded by Metellus Scipio, who was aligned with the senatorial faction opposing Caesar. This battle took place in North Africa and resulted in a decisive victory for Caesar, consolidating his power in the Roman Republic.

The significance of this battle lies not only in its outcome but also in how it marked the decline of resistance against Caesar’s rule. Scipio's forces were ultimately outmatched and suffered heavy losses, leading to Scipio himself fleeing the field. This victory allowed Caesar to further solidify his control and set the stage for his dictatorship.

The other options listed, such as the Battle of Zama, occurred at a much earlier time and involved different adversaries, specifically between Rome and Carthage during the Second Punic War. The Battles of Alesia and Carrhae also pertained to distinct historical contexts involving different generals and situations unrelated to Scipio’s forces under Caesar. Thus, Thapsus is correctly identified as the battle in which Caesar achieved victory over Metellus Scipio's troops.