A stationary source S generates circular outgoing waves on a lake. The wave speed is $5\mathrm{.}0$ m$/$s and the crest$-$to$-$crest distance is $2\mathrm{.}0$ m$.$ A person in a motor boat heads directly toward S at a speed of $3\mathrm{.}0$ m$/$s$.$ To this person, the frequency of the waves is: A$.1\mathrm{.}0$ Hz B$.1\mathrm{.}5$ Hz C$.2\mathrm{.}0$ Hz D$.4\mathrm{.}0$ Hz E$.8\mathrm{.}0$ Hz