Yes, you can specify a minimum number of choices for a multiple choice field.
Once you have added a Multiple choice field, in the left side panel, under the Validation section, you will find the Min. no of choices option.
If you want your respondents to select a specific number of choices (e.g. exactly 2 choices), you’ll need to specify the same value for both the maximum and the minimum number of choices. Make sure the value typed in for the Min no. of choices doesn’t exceed the value you have for your Max no. of choices, otherwise you’ll receive an error.
When your respondents don’t select the minimum number of choices you’ve set up, they will receive an error message. You can change the text of the message in the Languages → System Messages section.