$latex \mathbf{\frac{3}{7}}&s=1$
Given Expression :
$latex \frac{(243)^{0.13}\times (243)^{0.07}}{(7)^{0.25}\times (49)^{0.075}\times (343)^{0.2}}&s=2$
$latex = \frac{(243)^{0.13+0.07}}{(7)^{0.25}\times (7\times 7)^{0.075}\times (7\times 7\times 7)^{0.2}}&s=2$
$latex = \frac{\left ( 3^{5} \right )^{0.2}}{\left ( 7 \right )^{0.25}\times \left ( 7 \right )^{0.075\times 2}\times \left ( 7 \right )^{3\times 0.2}}&s=2$
$latex = \frac{(3)^{5\times 0.2}}{(7)^{0.25+0.15+0.6}} = \frac{3}{7}&s=2$
Hence option [C] is correct answer.