The ARPA performance standards require that the system be capable of displaying, on request, past positions of any tracked target. What are the minimum requirements for this capability?

1. A. At least two past positions over a period of at least four minutes
2. B. At least three past positions over a period of at least six minutes
3. ✓ At least four equally time-spaced past positions over a period of at least eight minutesCorrect
4. D. At least six equally time-spaced past positions over a period of at least ten minutes