Final answer:
The correct answer is option OC - por si las moscas, which means 'just in case' in English.
Step-by-step explanation:
The correct answer to fill in the blank in the sentence is option OC. 'por si las moscas.' This phrase translates to 'just in case' in English, and it is used to express precaution or to be prepared for any possible outcome.
Learn more about Spanish expressions