Multinational Financial System

$1.$ Suppose that the German unit of Billbert Enterprises buys $\backslash (\backslash$$ $500,000\backslash )$ per month of goods from the French unit and sells $\backslash (\backslash$$ $1\backslash )$ million per month to the British unit. At present, all interunit sales require payment in thirty days. Using leads and lags, how can the following transfers of funds be made?

a$.$ from the German unit to the French unit

b$.$ from the British unit to the German unit

c$.$ from the British unit to the French unit

d$.$ from the French unit to the British unit