Here are the correct options for each item:
- Mr. Nelson is worried. - Estar (because it describes a temporary state)
- He is bald. - Ser (because it describes a permanent characteristic)
- It is July 4th. - Ser (because it describes a date)
So the selections are:
- Mr. Nelson is worried. - Estar
- He is bald. - Ser
- It is July 4th. - Ser