When we are calculating a confidence interval, we can express the margin of rror as:
![MOE=z\cdot\sigma_M](https://img.qammunity.org/2023/formulas/mathematics/college/fdw01d0fgt9a7abq0kmljwditbe7rj4sus.png)
where z is the critical value for the significance level chosen and σM is the standard error (NOTE: it can be expressed with different symbols).
Then, from the options, the margin of error is equal to the critical value times the standard error [Option A].