Which of the Following Is a Correct Statement Regarding the Validity

Which of the following is a correct statement regarding the validity of various means of acceptance (assuming no means of communicating the acceptance is specified?)

A) Telephone,mail,and e-mail are all valid means of acceptance,while telegraph and fax are not valid means of acceptance.
B) Telegraph and fax are valid means of acceptance,while telephone,mail,and e-mail are not valid means of acceptance.
C) Telephone,mail,e-mail,and fax are all valid means of acceptance,while telegraph is not a valid means of acceptance since it is an outdated form of communication.
D) Telephone,telegraph,mail,fax,and e-mail are all valid means of accepting an offer.
E) Telephone,telegraph,mail,fax,and e-mail are all invalid means of accepting an offer,since an offer must be accepted either in person or by way of a formal letter of acceptance.