1. In the event dashboard click on the "Registration" tab from the sidebar.

2. Click on the "Registration Form"

3. Now, select the field you would like to edit in the registration form and click on the 'Edit' option located on the field card.

4. To limit the option for attendees, enable the "Restrict Availability" field.

5. Navigate to the relevant option, choose the quantity, and only the selected number of attendees will be able to choose this option.

6. After entering the number of attendees who can select the options, click on the 'Save' button located at the bottom.