AHSME 1961 Problem 13

The symbol $|a|$ means $a$ is a positive number or zero, and $-a$ if $a$ is a negative number. For all real values of $t$ the expression $\sqrt{t^4+t^2}$ is equal to? $\textbf{(A)}\ t^3 \textbf{(B)}\ t^2+t \textbf{(C)}\ |t^2+t| \textbf{(D)}\ t\sqrt{t^2+1} \textbf{(E)}\ |t|\sqrt{1+t^2}$