An isosceles triangle ABC is rightangled at B.D is a point inside the triangle ABC. P and Q are the feet of the perpendiculars drawn from D on the side AB and AC respectively of ABC. If AP = a cm, AQ = b cm and BAD = 15 , sin 75 =

• A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2b</center></td></tr><td style="text-align: center;"> <span style=" text-decoration: overline;">3</span>a</td></table>
• B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>a</center></td></tr><td style="text-align: center;">2b</td><td></td></table>
• C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <span style=" text-decoration: overline;">3</span>a</center></td></tr><td style="text-align: center;">2b</td></table>
• D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2a</center></td></tr><td style="text-align: center;"> <span style=" text-decoration: overline;">3</span>b</td></table>