Answer:
Seisin
Explanation:
The covenant of seisin is essentially a covenant that the grantor owns the estate that the deed says it conveys to the grantee. This covenant promises that no one else has any conflicting possessory interests, present or future. the sale of property to Ari's neighbor was never recorded, his deed still shows that he owns the entire parcel. Thus if Ari sells the land to the developer without informing his neighbour, he would be breaking the covenant of selsin.