The correct option is C decrease
We know that, rate of heat transfer in convection, q=hcAΔT ..............(1)
where hc is convection coefficient, A is surface area of body and ΔT= temperature difference between body and surrounding.
⇒ΔT=T−To
As surrounding temperature To increases, ΔT will decrease.
Thus, rate of heat transfer q will decrease. [ from (1) ]