Rewrite the following switch statement as one nested if$-$else statement $($elseif clauses may be used$).$ Assume that there is a variable letter and that it has been initialized.

switch letter

case $\text{'}x\text{'}$

disp $(\text{'}$Hello$\text{'}).$

case $\text{'}Y\text{'},\text{'}Y\text{'}\}$

disp $(\text{'}$Yes$\text{'})$

case $\text{'}Q\text{'}$

disp $(\text{'}$Quit$\text{'})$

otherwise

disp $(\text{'}$Error$\text{'})$

end