Confidence intervals for an exponential rate parameter

Let $X_1,…,X_n$ be a random sample from a population with the probability density function

$$f(x|\theta)=\begin{cases}\theta e^{-\theta x}, & x>0,\ 0, & \text{otherwise,}\end{cases}\quad\theta>0.$$

Which of the following is (are) $100(1-\alpha)\%$ confidence interval(s) for $\theta$?