Should be antenna DRC. Once the chip is manuafactured to be good and antenna will not afect the reliability.
EM will result in reliability issues of potential short/spacing in long term.
My Answer will be "EM".
Antenna DRC will be considered only during the Chip fabrication.
Crosstalk will lead to a logic malfunction & it wont affect the life time of the chip.
Only thing will affect life time of the chip is Electromigration. This may create shorts or opens over the period of time.