Name a sign that a tree is dying or unhealthy.

A sign that a tree is dying or unhealthy is the presence of dead or decaying branches, a lack of leaves, or fungal growth. These indicators show that the tree is failing to thrive. Dead or decaying branches suggest that the tree is not able to sustain its limbs, which can be due to disease, pest infestations, or environmental stress. The absence of leaves may indicate that the tree is not able to photosynthesize effectively, either due to root issues, a severe loss of health, or a disease affecting its overall structure. Fungal growth often points to rot, which can compromise the integrity of the tree and signal that it is unable to maintain its health.

In contrast, the other choices describe characteristics of a healthy tree. Bright and abundant leaves indicate good photosynthesis, while a thick trunk and healthy bark suggest robust growth and durability. Consistent growth throughout the year reflects a tree's vigor and suggests that it is in a healthy state. Each of these contrasts with the signs of decline indicated by the correct choice.