The antonym of the word ‘licentious’ is-

Correct answer: Virtuous.

Licentious (adjective)
- English meaning: lacking legal or moral restraints, especially: disregarding sexual restraints.
- Bangla meaning: লম্পট; অসচ্চরিত্র; কামুক।

Virtuous (adjective)
- English meaning: having or exhibiting virtue: morally excellent: righteous.
- Bangla meaning: ন্যায়পর, সদগুনসম্পন্না।

Other options:
ক) Wanton
- English meaning: of something bad, such as damage, cruelty, waste) extreme and showing no care at all.
- Bangla meaning: চরিত্রহীন বা লম্পট ব্যক্তি

খ) Lascivious
- English meaning: filled with or showing sexual desire: lewd, lustful.
- Bangla meaning: কামুক; কামোদ্দীপক।

গ) Unlicensed
- English meaning: not authorized or permitted by a license.
- Bangla meaning: অনুমতিহীন; লাইসেন্সবিহীন।

Source:
1. Accessible Dictionary by Bangla Academy.
2. Merriam-Webster Dictionary.
3. Cambridge Dictionary.