can you play this game in 4K 3840x2160p Resolution

[Darksider]

I have a XB280HK ACER MONITOR..I was told it only plays at highest 1440p

[K]

Check the Video In Game settings.

[Ancient]

Windows button + R, write %appdata% and press enter.
open folders, \Fatshark\Warhammer End Times Vermintide\.
In this folder, open "user_settings.config" and set the resolution you want.
This allows you to override the 2.5k resolution (2560x1440) limit in the in-game options.

I can attest that it does run at 4k, but with an i7 5820k and a single GTX970, my rig cannot play it at 4k because it runs at ~20 FPS, so the answer to your question, at least for me, is no.

Since SLI/Crossfire don't work in VT, I'm going to guess a single top-end GPU like a 980 Ti or TITAN Z is what would be needed for 4k res and playable FPS.

[SopuliApina]

I am getting quite stable 60 fps with low-medium settings at 4K resolution. You should stick with 2K because it is possible to max graphic settings. I am quite sure the game doesn't run stable 60fps @ 4K resolution with all settings maxed with any rig at the moment. My rig: 2x Gtx Titan X running with 1400mhz overclock, I7 5930K @ 4,8ghz, 32GB 3200 DDR4.