A offered to sell his house and lot for P10M to B, who was interested in buying the same. In his letter to B, A stated that he was giving B a period of one month within which to raise the amount, and that as soon as B is ready, they will sign the deed of sale. One week before the expiration of the one-month period, A went to B, and told him that he is no longer willing to sell the property unless the price is increased to P15M. May B compel A to accept the P10M first offered, and execute the sale?

EXPLAIN and GIVE Reason/s.