Correct option is CGiven:712÷{414−12×(212−114−34)}7\frac{1}{2} \div \left\{ 4\frac{1}{4} - \frac{1}{2} \times \left( 2\frac{1}{2} - 1\frac{1}{4} - \frac{3}{4} \right) \right\}721÷{441−21×(221−141−43)}Solution:712÷{414−12×(212−114−34)} =152÷{174−12×(52−54−34)} =152÷{174−12×(10−5−34)} =152÷{174−12×24} =152÷{174−14} =152÷164 =152×416 =3016=1.8757\frac{1}{2} \div \left\{ 4\frac{1}{4} - \frac{1}{2} \times \left( 2\frac{1}{2} - 1\frac{1}{4} - \frac{3}{4} \right) \right\}\\ \ \\= \frac{15}{2} \div \left\{ \frac{17}{4} - \frac{1}{2} \times \left( \frac{5}{2} - \frac{5}{4} - \frac{3}{4} \right) \right\}\\ \ \\= \frac{15}{2} \div \left\{ \frac{17}{4} - \frac{1}{2} \times \left( \frac{10 - 5 - 3}{4} \right) \right\}\\ \ \\= \frac{15}{2} \div \left\{ \frac{17}{4} - \frac{1}{2} \times \frac{2}{4} \right\}\\ \ \\= \frac{15}{2} \div \left\{ \frac{17}{4} - \frac{1}{4} \right\}\\ \ \\= \frac{15}{2} \div \frac{16}{4} \\ \ \\= \frac{15}{2} \times \frac{4}{16}\\ \ \\ = \frac{30}{16} = 1.875721÷{441−21×(221−141−43)} =215÷{417−21×(25−45−43)} =215÷{417−21×(410−5−3)} =215÷{417−21×42} =215÷{417−41} =215÷416 =215×164 =1630=1.875