myText=<b>Two factors are crucial for determining the temperature of the Earth's surface and/or atmosphere.  Which are the two factors?
A)   <i>The Earth's tilt and the fact that the Earth is round.</i>
B)   <i>Day length and the angle of the energy from the sun.</i>
C)   <i>Day length and the total amount of energy received from the sun.</i>
D)   <i>The total amount of energy received from the sun and the Earth's tilt.</i>