Check box lists would be the answer; based on Microsoft guideline for desktop app which you could use it for web app somehow:
Standard multiple-selection lists have exactly the same appearance as single-selection lists, so there is no visual clue that a list box supports multiple selection. Because users have to discover this ability, this list pattern is best used for tasks where multiple selection isn't essential and is rarely used.
There are two different multiple-selection modes: multiple and extended. Extended selection mode is by far the more common, where the selection can be extended by dragging or with Shift+click and Ctrl+click to select groups of contiguous and non-adjacent values, respectively. In the multiple-selection mode, clicking any item toggles its selection state regardless of the Shift and Ctrl keys. Given this unusual behavior, multiple-selection mode is deprecated and you should use check box lists instead.

Unlike standard multiple-selection lists, the check boxes clearly indicate that multiple selection is possible. Use this list pattern for tasks where multiple selection is essential or commonly used.

In this example, users typically select more than one item so a check box list is used.
Given this clear indication of multiple selection, you might assume that check box lists are preferable to standard multiple-selection lists. In practice, few tasks require multiple selection or use it heavily; using a check box list in such cases draws too much attention to selection. Consequently, standard multiple-selection lists are far more common.