A steady current flows in a metallic conductor of nonuniform cross-section. The quantity/ quantities constant along the length of the conductor is/are

If E is the electric field, then current density j=σE Also we know that current density j=iAHence T is different for different area of cross-sections. When T is different, then E is also different. Thus E is not constant. The drift velocity vd is given by vd=jne = different for different j values, Hence, only current ii will be constant.