Question

at one time, the branches of the apple tree were full of apples, but now the old, neglected tree is barren and unable to .
options: grow branches, lose its leaves, produce fruit

Explanation:

The word "barren" in the context of a tree means it is unable to bear fruit or reproduce fruit. Among the options, "produce fruit" fits the meaning of a barren tree (unable to produce fruit) as the tree was once full of apples (could produce fruit) but now is barren. "Grow branches" and "lose its leaves" don't relate to the meaning of barren for a fruit - bearing tree.

Answer:

produce fruit