If the student studied 10 hours in a day, then he/she studied mathematics for

• A. 3 hours
• B. <table><tr><td rowspan="2"> </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10</center></td><td rowspan="2">hours</td></tr><td align="center">3</td></table>
• C. <table><tr><td rowspan="2"> </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>1</center></td><td rowspan="2">hours</td></tr><td align="center">3</td></table>
• D. <table><tr><td rowspan="2"> </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>3</center></td><td rowspan="2">hours</td></tr><td align="center">10</td></table>