Fill in the blank with the most appropriate word. Eggs are sold ______ the…

Explanation: The phrase 'sold by the dozen' is a common fixed expression in English. Here, 'by' indicates the unit or grouping used for sale — meaning 'per dozen' (often referring to the price or the way items are packaged).

• Why 'by' is correct: 'by' expresses measure or rate (e.g., sold by the dozen, sold by the pound).

• Why the other choices are wrong: 'to' indicates direction or purpose; 'at' indicates location or time; neither expresses a unit of sale.

• Note on 'in': You can say 'sold in dozens' to mean sold in groups of twelve, but the more natural collocation for pricing or units is 'sold by the dozen.'

Examples:

• Eggs are sold by the dozen.

• Some stores sell eggs in dozens (less common when referring to pricing).