The act of disposing of property: refers to an act that directly results in the transfer or elimination of property rights. The result of the act of disposing of property is the transfer of rights, the reduction or change of the content of rights, the burden on rights, and the elimination of rights. According to the above definitions, which of the following acts are not property disposal acts? ["In order to guarantee a debt, Company A mortgaged all its own properties. The mortgage behavior restricted Company A's ownership of the property.", "B abandons his own TV set, and the abandoning behavior destroys B's ownership of the TV set.", "C entered into a contract with D to sell C's heirloom ancient paintings, and agreed that C should deliver the ancient paintings after 7 days, and the contract act made C bear the obligation to transfer the ownership of the ancient paintings after 7 days.", "D forgive C's pecuniary debt, and the forgiveness makes C need not perform his obligation to repay the money."]