Final answer:
The expiration of obligated service (EAOS) for a sailor who reenlisted on 02 November 2017 for 4 years is on 02 November 2021, which is calculated by adding the duration of service to the reenlistment date.
Step-by-step explanation:
The expiration of obligated service (EAOS) for a sailor who reenlisted for 4 years on 02 November 2017, can be determined by simply adding 4 years to the reenlistment date. This is a straightforward calculation of time or date addition.
To calculate the EAOS, you take the reenlistment date, which is 02 November 2017, and add the duration of service, which is 4 years, to that date. Therefore, you would reach the date 02 November 2021 as the day the sailor's service obligation would expire.
Thus, the correct answer to the student's question is Option A) 02 November 2021.