It is a Mk IV male. These participated in the following battles:

Messines 7/7/17 76 vehicles
3rd Ypres 7/31/17 216 vehicles
Langemarck-St. Julien 8/16 - 19/17 12 vehicles
3rd Gaza 11/1/17 3 vehicles
1st Cambrai 11/20/17 378 vehicles
2nd Somme 3/21/18 5 vehicles
Bucquoy raid 5/23/18 5 vehicles
Bapaume 8/21/18
2nd Arras 8/25/18
2nd Cambari 9/27/18
Selle 10/23/18

You can tell the difference between the Mk IV and V by the position of the command structure on top, and by the presence or absence of louvers on the side at the rear. Otherwise, the two are hard to tell apart.