Choose the meaning of the word 'riddled' in the following sentence: 'The cavity, once opened, proved to be riddled with infection.'
Correct Answer: B
Rationale: The word 'riddled' in this context means filled with or affected by (something undesirable) to a great degree, which aligns with the definition of 'overrun.' In this sentence, the cavity is described as being full of infection, indicating that the infection has spread extensively throughout. 'Challenged' (choice A) implies being tested or provoked, which is not the meaning conveyed by 'riddled.' 'Separated' (choice C) means divided or isolated, which does not fit the context of the sentence. 'Complete' (choice D) means finished or whole, which is the opposite of what is described in the sentence where the cavity is full of infection.