What is the legal definition of theft?

The correct choice accurately reflects the legal definition of theft, which generally involves the act of taking or appropriating someone else's property without their consent and with the intent to permanently deprive the owner of that property. This concept is fundamental in understanding theft, as it emphasizes the intent required to commit this crime. The phrase "obtaining property with intent to deprive the owner" encapsulates the critical elements involved: the act of obtaining and the specific intent regarding the property owner’s rights.

The other options delineate different legal concepts. Entering or remaining unlawfully on property relates to trespassing and not theft. Making or altering a writing to defraud pertains to forgery, which involves deception for the purpose of fraud rather than the unlawful taking of property. Deception to obtain benefit or cause loss refers to fraud, which is focused on deceit rather than the direct appropriation of property as in theft. Thus, the selection accurately defines theft by highlighting both the act of acquiring property and the intent to deprive the rightful owner.