The sunlight is available 24 hours on the longest day at which of the following latitudes of the earth ?

• A. 49
• B. <table><tr><td rowspan="2">66</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>1</center></td><td rowspan="2"> </td></tr><td align="center">2</td></table>
• C. 63
• D. 69 51'