Which of the following is NOT true about the thermodynamic standard state?

Question

A. A pure liquid is in its standard state at 25C and a vapor pressure of 1.00 atm.

B. A gas is in its standard state when its pressure is 1.00 atm and its temperature is 25C .

C. A solid is in its standard state when the atmospheric pressure is 1.00 atm and the temperature is 25C .

D. An aqueous solution is in its standard state at a concentration of 1.00 M.

E. All of these are true.

http://en.wikipedia.org/wiki/Standard_state

so which one is correct beacause both a,b, c are at 1 atm and 25 degrees

Have you misread the question? The question asks for which is NOT true. Your response of "so which one is correct because both a,b,c are at 1 atm and 25 dgrees?" is not true, either.