Rewrite the sentence in direct speech.
Sumanth said that he would have called a doctor.

Correct option is C

The sentence in indirect speech "he would have called a doctor" indicates a future perfect tense in the past, which directly converts to "I will have called a doctor" in direct speech.
Rule of Conversion: Future perfect tense in the past (would have called) is directly converted to future perfect (will have called) in direct speech. Pronouns and temporal phrases are adjusted accordingly.
Example: He said he would have finished -> He said, "I will have finished."