$5.$ In the balancing of a single cylinder engine, how is the primary force typically counteracted?

$-$ A$)$ By using balance shafts

$-$ B$)$ Through crankshaft design modifications

$-$ C$)$ By adjusting the piston trajectory

$-$ D$)$ Through combustion chamber shaping

$6.$ What technique is used to balance inline four$-$cylinder engines to address secondary forces?

$-$ A$)$ Cross$-$plane crankshaft

$-$ B$)$ Harmonic balancer

$-$ C$)$ Lanchester balancing system

$-$ D$)$ Opposed piston configuration