$47.$ The selection between solid and hollow shafts often involves a trade$-$off between:

$-$ A$)$ Cost and aesthetics

$-$ B$)$ Weight and strength

$-$ C$)$ Color and texture

$-$ D$)$ Length and diameter

$48.$ Rigid flange couplings are not suitable for applications with:

$-$ A$)$ High torque transmission

$-$ B$)$ Precise shaft alignment

$-$ C$)$ Significant shaft misalignment

$-$ D$)$ Low rotational speeds