"I have learnt a great deal working in factories, and for a time I've been a weaver. Here are my testimonials, Mr. Davis."

Answer: Option A

Credentials : a qualification, achievement, quality, or aspect of a person's background, especially when used to indicate their suitability for something.
Tokens : a thing serving as a visible or tangible representation of a fact, quality, feeling, etc.
Testaments : a person's will, especially the part relating to personal property.
Witnesses : a person who sees an event, typically a crime or accident, take place.
Testimonials : a formal statement testifying to someone's character and qualifications.

Synonym of Testimonials is Credentials