Jack Jones and his company Jack Holdings Pty Ltd have different legal entities since his business is a registered Sole Proprietorship.

Jack will be obliged to sell his property to Rose Darling because the contract to sell was entered into before registering Jack Holdings Pty Ltd.

Step-by-step explanation

A person can be the Sole Director and the Sole Secretary in a registered Sole Proprietorship. Separate entity is maintained as long as proper books of accounts are maintained.

There is no valid reason for Jack Jones to breach his contract with Rose Darling which was entered into freely and willingly, and before Jack Holdings Pty Ltd was registered as a company.

Specific performance under this circumstancesis offered as a remedy to the aggrieved party, thus the contract should be completed.

Specific performance gives the aggrieved party in this dispute the right to take possession, if the contract is not fulfilled, of the property in dispute.