For a hypothetical reaction; $\mathrm{A}\to \mathrm{L}$ the rate expression is, rate = $-\frac{{\mathrm{dC}}_{\mathrm{A}}}{\mathrm{dt}}$

negative sign represents that rate is negative

all of the above are correct

negative sign indicates the attractive forces between reactants

negative sign pertains to the decrease in the concentrations of reactant