Which of these deed restrictions of a subdivision would be considered to be the most difficult for the Developer to enforce?Oeach owner must make $$500$ worth of improvements per lot, per yearO B$.$each lot must be limited to $73-$ by $175-$feetthe height of any single building or improvement may not exceed $25$ feetO D$.$all homes will contain a minimum of $1,500$ square feet of living space