Answer:
The options do not match the case, since Sandi proposed the corporation and Walter is having second thoughts about it due to corporate taxes.
Walter might be right or wrong depending on the type of corporation that they choose to form. If they choose to form a S corporation they will not be double taxed, since S corporations are pass through entities. But if they choose to form a C corporation, then they will be subject to double taxation since the C corporation will have to pay income taxes and Sandi and Walter will also be required to pay income taxes.
Both C and S corporations provide their stockholders limited liability, so neither Sandi or Walter will be personally liable for any obligation that the corporation may acquire or be imposed to (e.g. lawsuits).