Final answer:
The fourth field to be harvested is K, considering all the constraints provided and deducing the order that satisfies all of them.
Step-by-step explanation:
To determine which field is harvested fourth, we must apply the conditions to the order of harvesting. Considering the constraints given:
- J is harvested before H and immediately after M.
- K is harvested after T and before G.
- L is harvested before P.
From the constraints, we can deduce that M is harvested before J, and accordingly, they must be harvested consecutively. We also know that K cannot be first because T comes before it. Since L comes before P, without specific slots allocated, L and P cannot be determined at this point. Therefore, K must be the fourth to be harvested because it cannot come before T, and M and J must come together in the sequence third and fourth or second and third. To satisfy all conditions, the fourth field harvested is K.