Ravi has been fully cured . . . . . . . . the chronic pain in his legs. A. from B. by C. of D. with

The correct answer is: A. from

The preposition “from” is used to indicate the source or cause of something. In this case, Ravi has been cured from the chronic pain in his legs.

The other options are incorrect because they do not accurately reflect the meaning of the sentence.

• The preposition “by” is used to indicate the agent or means by which something is done. In this case, the sentence does not indicate who or what cured Ravi of his chronic pain.
• The preposition “of” is used to indicate possession or ownership. In this case, the sentence does not indicate that Ravi owns the chronic pain in his legs.
• The preposition “with” is used to indicate accompaniment or association. In this case, the sentence does not indicate that Ravi is accompanied by the chronic pain in his legs.