Bunuel
The Purple Heart, a United States military decoration, can be awarded for an injury sustained during battle on foreign soil, on a US ship in combat,
and during an attack on US soil, but not awarded for one due to the soldier’s own negligence.
A. and during an attack on US soil, but not awarded for one
B. and during an attack on US soil, but excluding it when
C. and during an attack on US soil, but not awarded when it is
D. or during an attack on US soil, but not for one
E. or during an attack on US soil, but it cannot be awarded if it is
A.
and during an attack on US soil, but not awarded for one - use of "and" is incorrect here because the list given represents one of the situations in which the medal will be awarded. If we use "and" then it would mean that the medal will be awarded when two of three situations exist which is illogical.
B.
and during an attack on US soil, but excluding it when - Eliminated for the same reason as above
C.
and during an attack on US soil, but not awarded when it is - Eliminated for the same reason as above
D.
or during an attack on US soil, but not for one - Or is used correctly, but...for is parallel to can be awarded for.. so the structure is correct. Meaning is also clearly conveyed because we can link can be awarded for this... to but not for this.
E.
or during an attack on US soil, but
it cannot be awarded if
it is - Here there is pronoun issue. There are "2 it" - first it refers to "the medal or The Purple Heart" and second it refers to "the injury" - because both refer to singular nouns we cannot differentiate the pronoun-antecedent of the first it from the second it.
Therefore,
option D is the correct answer.