Here my take on this.
A pesticides, irradiation, or genetic modification
B pesticides, irradiation, or nothing that has been genetically modified
Foods cannot contain irradiation so these two options can be eliminated.
C and pesticides, or if they have been irradiated or genetically modified
Use of 'and'. Food may contain any of antibiotics, hormones, pesticides, not necessarily all of them. So we eliminate this option.
E or pesticides, and anything that has been irradiated or genetically modified
We are concerned only with foods here, so 'anything' is wrong.
That leaves us with option D.
D or pesticides, or if they have been irradiated or genetically modified
This option correctly uses 'or pesticides or if they have been' and 'they' refers to 'foods' correctly.
So the answer is D.
Give [highlight]KUDOS [/highlight] if you like my post.
Always do things which make you feel ALIVE!!!