One question that trips a lot of people up during the hiring process involves salary history. Knowing what you are currently paid might give some indication of what your current company thought you were worth when they hired you. However, it may or may not have anything to do do with fair compensation for the new company and position for which you are interviewing.
A better way to answer this question is to have done your homework, and report that the ACS Salary Comparator (or other impartial expert) indicates that the typical salary range for the new position would be between X and Y. Then ask if that’s the range they are planning to offer. This shows that you are educated about the position for which you are applying, and that you understand what is relevant, and what is not.
Also remember that negotiation should not start until you have an offer in hand, and that salary is only part of the total compensation package. (And sometimes not even the most important part.)