Guya agrees to sell her house to Fredricka for $700,000.00. They shake on it but do not confirm their agreement in writing. Which statement is most accurate:

Their agreement is not valid because it is not in writing and all purchase and sales agreement for land must be in writing

Their agreement is not valid because it is not in writing

Their agreement is not valid because it is not in writing and therefore there is no proof of the sale

Their agreement is not valid because it is not in writing and only contracts in writing are valid