Step 1: Understanding the facts.
A threatened to kill B unless she handed over her jewellery. Due to this threat, B was put in fear of death and was compelled to give her jewellery. The threat was intentional and dishonest.
Step 2: Legal concept involved.
Under Section 383 of the Indian Penal Code, extortion is committed when a person intentionally puts another in fear of injury and thereby dishonestly induces that person to deliver property.
Step 3: Application to the present case.
A intentionally threatened B with death, putting her in fear, and dishonestly induced her to give her jewellery. The marital relationship does not exempt criminal liability for extortion.
Step 4: Examination of options.
(A) Incorrect, because husband and wife are separate legal persons and criminal liability applies between them.
(C) Incorrect, because the primary offence here is extortion, not grievous hurt.
(D) Incorrect, as a wife can legally file a criminal complaint against her husband.
Step 5: Conclusion.
Since A intentionally put B in fear and dishonestly obtained her jewellery, he committed the offence of extortion. Therefore, B can file a complaint against her husband.