I'm editing a Stack question, and I've added a drop down input.
All the variables all here (in case the problem can be connected to them):
This last variable (ta3) is the problematic one.
The question to this variable in the question text part is: 3.) Choose the correct unit for amount of substance input:ans3 validation:ans3 feedback:prt3
I set input ans3 to Drop down list input type, and the model answer is ta3. In the response tree prt3: answer test is AlgEquiv, SAns: ans3 and the TAns: mol.
The preview says: The input has generated the following runtime error which prevents you from answering. Please contact your teacher. The model answer field for this input is malformed: [km,false]. The teacher did not indicate at least one correct answer.
Can anyone spot the problem? Thank you in advance.