问题：
[多选题]Natural people A and B signed a 1 year 10,000,000 yuan loan contract at an annual interest rate of 30%. A and B then signed a property sale and purchase contract, agreeing that: “A sold the property to B, the property payment is to cover A’s loan’s principal and interest. A must make the full payment in 6 installments within one year to buy back the property. If A did not buy back the property then B has the right to obtain the ownership of the property.” B delivers the loan and A issues the receipt for the full payment of the property. A did not buy back the house according to the agreement, nor did A transfer the property to B. The property value increased to 30 million yuan, and A claims to repay the loan principal and interest.
Which of the following choices is correct?
A、A and B has a loan contract but not a property sale and purchase contract.
B、Interest of the loan should not exceed 4 times the bank’s loan interest rate in the same time period.
C、B cannot obtain the ownership of the property.
D、If A did not pay back the loan as agreed, A shall bear the liability for breach of contract.
