Statistical Inference — completeness of $X_1$ versus $X_1^2$ for normal variance

If $x_1, x_2, x_3, …, x_n$ is a random sample from $N(0, \theta)$, then which of the statements given below is/are correct? I. $T_1 = x_1$ is complete statistic for $\theta$. II. $T_2 = x_1^2$ is complete statistic for $\theta$. Select the answer using the code given below.