At which latitude,heat gain through insolation approximately equals heat loss through terrestrial radiation?

• A
  $66^{\circ}$ North and South
• B
  $22 \frac{1}{2}^{\circ}$ North and South
• C
  $40^{\circ}$ North and South
• D
  $42 \frac{1}{2}^{\circ}$ North and South