Select the appropriate preposition to fill in the blank in the following…

Concept: English uses two different prepositions to describe how something is distributed. "Between" is the conventional choice when exactly two distinct, individually identified entities are involved (or when items are paired off one-to-one). "Among" is the conventional choice when something is distributed within a group considered collectively — a group whose members are not being individually singled out, traditionally treated as three or more.

Application: This exact sentence — "Divide the mangoes ____ the boys" — is a standard preposition-usage drill built around that between/among distinction, and grammar practice sources that carry this specific exercise consistently key it to "among": the sentence names "the boys" as an undifferentiated group rather than naming or pairing off exactly two individuals, which is the textbook signal for the collective-group preposition. If the sentence instead read "the two boys" or named two individuals, "between" would be the conventional choice — the rule is about how the entities are referred to (a distinct pair vs. an undifferentiated group), not merely a raw headcount.

Cross-check — contrast each option by its own value:

• Between fits only when exactly two distinct entities are named or paired individually, e.g. "The land was divided between the two brothers."

• With expresses accompaniment or the instrument/means of an action, e.g. "She cut the mango with a knife" — this is not a distributive relation.

• To introduces the recipient or direction of a transfer, e.g. "He gave the mangoes to the boys" — it does not itself express dividing something up among recipients.

• Among expresses distribution within a collective, undifferentiated group, matching how "the boys" is referred to in this sentence.

Result: the sentence reads "Divide the mangoes among the boys."