Between these two I'd take the curved one, as in such a short blade length the ability to "catch" the material and grab whatever it's cutting, typical if a curved blade (karambits, hawkbills...), greatly increases depth of cut and penetration, making longer, deeper and more safe-bet cuts.
The other one has a straight no frills blade for all and every task, but is shorter and has less belly, width and curvature thus drastically reducing the cutting performance.
Not only with self defense in mind, cutting open package, grabbing and slicing plastic clamshell, cutting cordage, nylon or cloth, etc...all these are best done with a curved blade