The constraints given to us are:
1. If we plan corn then we also plant beans,
2. Kale planted this year means you can't plant kale next year and
3. No two plants can be re-planted in the next year.

A- Can't be correct because in the 2nd year if we have corn then we need beans and this isn't allowed.
B- Both beans and corn can't be planted in both years as per rule 3. Incorrect.
C- Correct choice as it follows all three rules.
D- Corn can't be planted w/out beans. Incorrect.
E- Kale can't be planted two years in a row. Incorrect.