Which symptom is associated with Bacterial Fire Blight?

Bacterial Fire Blight is a serious disease that primarily affects plants in the rose family, particularly apple and pear trees. The characteristic symptom associated with this disease is the wilting, browning, and eventual death of blossoms and leaves while they remain attached to the plant. This symptom is indicative of the disease's progress as it often leads to significantly affected plant parts that do not drop immediately, which differs from many other plant diseases where dead parts typically fall off.

The other symptoms mentioned reflect issues related to different types of plant problems. For example, yellowing leaves might indicate nutrient deficiencies or environmental stresses, while entire branches turning red can be a sign of various physiological conditions or other diseases, not specifically linked to Bacterial Fire Blight. Lastly, foliage developing a powdery appearance is characteristic of fungal infections, such as powdery mildew, rather than bacterial diseases.

Therefore, the presence of wilting and dying blossoms and leaves that remain attached is a defining symptom of Bacterial Fire Blight, making it the correct choice.