  We evaluate the third- and fourth-order baryon, charge and strangeness
susceptibilities near a chiral critical point using the Nambu-Jona-Lasinio
model. We identify robust qualitative behaviours of the susceptibilities along
hypothetical freeze-out lines that agree with previous model studies.
Quantitatively, baryon number fluctuations are the largest in magnitude and
thus offer the strongest signal when freeze-out occurs farther away from a
critical point. Charge and strangeness susceptibilities also diverge at a
critical point, but the area where the divergence dominates is smaller, meaning
freeze-out must occur closer to a critical point for a signal to be visible in
these observables. In case of strangeness, this is attributable to the
relatively large strange quark mass. Plotting the third- and fourth-order
susceptibilities against each other along the freeze-out line exhibits clearly
their non-montonicity and robust features.
