A conscientious worker is always admired by his employers.

Answer: Option B

Obedient : complying or willing to comply with an order or request; submissive to another's authority.
Sincere : complying or willing to comply with an order or request; submissive to another's authority.
Skillful : having or showing skill.
Careful : making sure of avoiding potential danger, mishap, or harm; cautious.
Conscientious : wishing to do one's work or duty well and thoroughly.

Synonym of Conscientious is Sincere