Final answer:
'Esa caja' is the correct way to say 'this cash register' in Spanish.
Step-by-step explanation:
Esa caja is the correct way to say 'this cash register' in Spanish. 'Ese cajero' means 'that cashier', 'esta caja' means 'this box', and 'aquella caja' means 'that box, far from both the speaker and listener.' Therefore, 'esa caja' is the appropriate translation in this context.
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