How is theft defined?

The definition of theft centers around the unlawful taking of someone else's property with the intent to permanently deprive the owner of it. The correct choice highlights the idea of taking possession of belongings that do not belong to you, which encapsulates the essence of theft. It emphasizes the act of assuming ownership or control over someone else's property without permission.

Taking someone’s property by force suggests a violent confrontation, which aligns more with robbery rather than theft. Invading someone's premises pertains to trespassing and does not necessarily involve the intent to take property. Meanwhile, illegal possession of firearms falls under a completely different category of crime, focused on firearms regulations rather than the definition of theft itself. Thus, the correct definition of theft is accurately presented in the chosen option as it directly addresses the fundamental nature of the crime.