A consistent moment-based estimator for the Laplace scale

Suppose $\{X_1,X_2,\dots,X_n\}$ is a random sample from a Laplace distribution with p.d.f. $f(x,\theta)=\dfrac1{2\theta} \exp(-|x|/\theta), x\in\mathbb{R}, \theta>0$. Which of the following estimators is consistent for $\theta$?