in a battle 70% of the combatants lost one eye,80% an ear,75% an arm,x% lost all 4 limbs.the minimum value of x is:

A:10

B:12

C:15

let there be 100 combatants, of which
1) 30 did not lost an eye; therefore, 70 did lost one, of which
2) 20 did not lost an ear; therefore, 50 did lost one, of which
3) 25 did not lost an arm; therefore, 25 did lost one, of which
4) 15 did not lost a leg; therefore, 10 did lost one

Finally, these 10 are the most unlucky ones.