After the following program is finished, how many bytes are written to the file t$.$dat?

$```$

import java$\mathrm{.}10.*$;

public class Test $\{$

public static void main$($String$[]$ args$)$ throws IOException $\{$

DataOutputStream output $=$ new DataOutputStream$($

new FileOutputStream$("$t$.$dat"$))$;

output.writeShort $(1234)$;

output.writeShort $(5678)$;

output.close$()$;

l

l

$```1$ byte$\mathrm{.}4$ bytes$\mathrm{.}9$ bytes$\mathrm{.}16$ bytes.