A: EAD and OPT are not immigration statuses.
An Employment Authorization Document (Form I-766/EAD) is one way to prove that an Individual is authorized to work in the United States for a specific time period.
Optional practical training (OPT) is temporary employment that is directly related to an F-1 student’s major area of study.
If the individuals are F1 visa holders, they will be exempt from paying FICA if they are a nonresident for tax purposes.
Nonresidents on qualified visas (such as A, G, F, M, Q and J) are generally exempt from FICA taxes as long as they meet all other requirements.