The most likely explanation for the plants developing brown leaves and beginning to wilt and die after the trees were removed is:
A. The leaves of the plants received too much sunlight, and the roots did not take in enough water.
When the trees were removed, the plants that had been growing in their shade were suddenly exposed to full sunlight, which they may not have been adapted to handle. Additionally, the removal of the trees may have changed the soil moisture levels, making it more challenging for the roots to take in enough water, leading to wilting and browning of the leaves.