Case $1.$ Oyak owned three building units $($A$,$ B and C$)$ in a commercial development. As a result of some financial difficulties, he e$-$mails to Asya as follows "I will sell you one of my units for $$150,000.$ Asya immediately e$-$mails back $$I accept your offer".

$($a$)$ Was Oyak$$s e$-$mail an offer? Why or why not?

$($b$)$ Is an e$-$mail exchange such as this one valid in forming a contract?