Final answer:
The best expression to complete the sentence is 'Estoy enferma.' It translates to 'I am sick.'
Step-by-step explanation:
The best expression to complete the sentence is 'Estoy enferma.' This translates to 'I am sick.' The sentence is expressing that the person is unable to go to work because they are not feeling well. The other options do not fit the context of the sentence.
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