For a cell terminal P.D. is 2.2V when circuit is open and reduces to 1.8V when cell is connected to a resistance of R = 5$\Omega$. Determine internal resistance of cell (r) is then : -

Question

( A ) $\frac{5}{9}\Omega$
( B ) $\frac{10}{9}\Omega$
( C ) $\frac{9}{10}\Omega$
( D ) $\frac{11}{9}\Omega$