The correct answer is: b) endergonic not spontaneous.
To understand this, we need to look at the definitions of the terms involved. A reaction with a positive delta G indicates that the reaction requires energy input to proceed, which makes it endergonic. Endergonic reactions are non-spontaneous, meaning they do not occur without the input of energy. On the other hand, exergonic reactions have a negative delta G, which means they release energy and are spontaneous. Therefore, the only option that correctly matches a positive delta G with the appropriate reaction type is option b.