What is (are) the main reason(s) a court would refuse to enforce an electronic contract?

a)The customer did not voluntarily agree to the terms and the terms were unfair.

b)The customer was not required to acknowledge the terms by clicking "I Agree."

c)The terms of the contract strongly favoured the seller.

d)The customer did not accept the agreement and the terms were highly unfair.

e)The customer did not understand the terms agreed to.