From Newton's law of cooling,
Rate of cooling: (−dtdT)=ms4σeAT03(T−T0)∝ms1
∴ρA<ρB
mA<mB
And sA<sB
mAsA<mBsB
At t=0,(−dtdT)A>(−dtdT)B
Initially, the rate of cooling for A will be higher than B and temperature (T) vs time (t) graph will be a curve.