Self-study (due to quarantine) of Contracts. I am a bit confuse with the following questions:

LAW - Contracts (Philippines)

1. S offered to sell his house and lot to B for P5,000,000 giving to him an option of 60 days within which to decide whether or not to buy. After only 15 days, S met T who offered to buy the same house and lot for P8,000,000. S then notified B of the withdrawal of the option and proceeded to sell to T. B files an action for damages against 5. a. B cannot recover damages from C because his option is without consideration as something paid or promised. b. B can recover damages from S because the latter violated the option given to the former. c. B can recover damages from Sif B gave Soption money which will result in a perfected contract of sale. d. Correct answer not indicated 2. On May 1, 2019, S offered to sell a specific car to B for P500,000.00. B sent his letter of acceptance to Son May 8, 2019. On May 10, 2019, however, S died in a vehicular accident and his secretary received the letter of acceptance on May 12, 2019 unaware that Shad already died. a. The contract was perfected on May 8, 2019 when B sent his letter of acceptance. b. The contract was perfected on May 12, 2019 when the secretary of S received the letter of acceptance. c. The contract was not perfected because the offer of S became ineffective when he died. d. The contract was perfected on May 1, 2019 because the acceptance made by B on May 8, 2019 retroacts to the date of the offer. 3. Dante borrowed P15,000,000.00 from Carlos. Dante died without having paid his loan obligation to Carlos. He left Santos and Marlon his heir properties worth P12,000,000.00 a. Santos and Marlon is liable to Carlos for P7,500,000.00 each. b. The estate of Dante is liable to Carlos for P12,000,000 and Santos and Marlon is liable to Carlos for P1,500,000.00 each. c. Santos and Marlon must deliver the properties worth P12,000,000 to Dante and to pay the balance of P3,000,000 with their separate property in solidum. d. Santos and Marlon must deliver the properties worth P12,000,000 to Carlos 4. Sisa defrauded Booba in making the latter believe that the ring he is selling is gold and diamond when in fact, it is copper and glass. On the other hand, Booba defrauded Sisa in paying him P200,000 in fake Philippine currency. Which of these statements is correct? a. Sisa can go to court for the annulment of the contract so that the ring will be returned to him. b. Booba can go to court so that his fake money will be restored to him. c. Neither Sisa nor Booba can go to court since they are both guilty of fraud. d. All the statements are not correct. 5. In a contract, as written, Dave promises to pay Carlo P20,000 on September 15, 2017. The consideration received by Dave is not stated in the contract: a. The contract is valid because the cause is always presumed to exist. b. The contract is valid so long as it is in writing. c. The contract is valid because cause is not essential to a contract. d. The contract is void because the cause is not stated