A is selling his property for 100,000. Contract with B says, B will buy the property from A for 100,000 in 1 month. B pays A 1000 as security deposit, which does not change the amount he owes to A. B has the option of not buying the property from A, but A is locked in until the end of 1 month. A keeps the 1000 regardless. Both have signed it of their free choice and are happy with the deal. The value of the house may go up or down with time and can easily be appraised, but for the contract is frozen. Humbly request to explain your response as supposed to a yes or no answer.
This is called a call option. The essence of it is that A gives B a promise to sell a specific thing to B for a specific amount within a specific period. In return for this promise, B pays a 1000.
The ruling regarding it is that such a promise in itself is permissible and morally binding, however it cannot be made the subject matter of a sale. Therefore, A cannot charge B a fee for making such a promise. Thus the contract would not be permissible as it is based on this invalid option. (Contemporary Fatawa of Mufti Taqi Uthmani Pg.99)
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai