Fluorination of an aromatic ring is easily accomplished by treating a diazonium salt with HBF4. Which of the following conditions is correct about this reaction ?

Question

$\begin{array}{1 1}(1)\; Only\; heat \\ (2)\; NaNO_2\;/\;Cu \\ (3)\; Cu_2O\;/\;H_2O \\ (4)\; NaF\;/\;Cu \end{array} $