Step 1: The question tests the medico legal sections of the Indian Penal Code that concern a doctor.
Step 2: IPC Section 197 deals with issuing or signing a false certificate. For a doctor this means knowingly giving a certificate that is false in a material point, for example a false fitness, death, or birth certificate. So option b is correct.
Step 3: The distractors map to different sections. Causing disappearance of evidence falls under IPC 201, and giving false evidence (perjury) falls under IPC 191 to 193, not 197.
Step 4: Since 197 is specifically about a false certificate, the combined option d is also wrong. The answer is issuing a false certificate by a doctor.