Evaluate the limits for the piecewise$-$defined function below. Answers are either integers or DNE $($for 'does not exist'$).$

$f(x)=\{\begin{array}{ccc}x& if& x<mn>0</mn>\\ x^2+3& if& 0x<mn>1</mn>\\ \frac{2}{x}& if& x1\end{array}$

$($a$)\underset{x{1}^{-}}{lim}f(x)=$

$($b$)\underset{x{1}^{+}}{lim}f(x)=$

$($c$)\underset{x1}{lim}f(x)=$

$($d$)\underset{x0}{lim}f(x)=$