An electrical water (k = 0.61 W/m· K) heater uses natural convection to transfer heat from a 1-cm-diameter by 0.65-m-long, 110 V electrical resistance heater to the water. During operation, the surface temperature of this heater is 120°C while the temperature of the water is 35°C, and the Nusselt number (based on the diameter) is 5. Considering only the side surface of the heater (and thus A = πDL), the current passing through the electrical heating element is
(a) 2.2 A

(b) 2.7 A

(c) 3.6 A

(d) 4.8 A

(e) 5.6 A