How do I get the last column text to be at the bottom of the row?

That is I want the XXX to be aligned with the line containing the arrow.
I tried playing around with \multirow{3}{-3ex}{XXX}, but obviously I don't understand \multirow.
Code:
\documentclass{article}
\usepackage{tabularx}
\usepackage{booktabs}
\usepackage{multirow}
\begin{document}
\begin{tabularx}{\linewidth}[t]{l X p{1.3cm}}
& Header & Title \\cmidrule(lr){2-2}\cmidrule(lr){3-3}
a. & Some text text text text text text text text text text text text text text
text text text text text text text text text text
Want XXX on this line $\rightarrow$%
& XXX\
\end{tabularx}
\end{document}



