Please answer this $($rephrased$!)$ question. A transverse wave moves in water at a speed v $.$ The distance between a crest and a trough along the direction of wave propagation is L$.$ Symbolically, what is the period of oscillation of a cork at the water surface?

L$/$v

$2$L$/$v

L$/(2$v$)$

Lv

$2$Lv