I came across this question on a sample TOEIC test. The answer is "(A) having" and I have no idea why this is correct.
Maria Vásquez has a wide range of experience, ------- worked in technical, production, and marketing positions.
(A) having (B) has (C) having had (D) had
I thought "(B) has", as "she has worked in technical, production, and marketing positions." was a correct sentence.
Here the phrase "having worked in technical, production, and marketing positions" is a past perfect participle, which acts like an adjective modifying "Maria Vasquez". Please see the linked article for more information on participles.
Other examples:
Having improved her English, Pia also improved her chances of being promoted.
Having been his own boss for such a long time, he found it hard to accept orders from another.
You can swap the participle with the main part of the sentence without changing the meaning:
He found it hard to accept orders from another, having been his own boss for such a long time.
(B) would be correct if the sentence was joined by a conjunction like "and":
Halley has been a personal trainer for many years, and has studied such techniques as hypnotic motivation and performance visualization to help her clients achieve maximum results.
"Has" and "had" are finite forms. They create clauses. They demand subjects. There is no available subject for them in the model sentence. To use them, you'd need to add something that the test question doesn't allow you to add:
Maria Vásquez has a wide range of experience. She has worked in technical, production, and marketing positions.
or
Maria Vásquez has a wide range of experience and has worked in technical, production, and marketing positions.
"Having" is a non-finite form. It doesn't need a subject. It fits.
"Having had" starts with the same non-finite form. However, it includes an additional non-finite form, one that conflicts with the non-finite form present in the model. To make this option fit, we'd need to remove something that the test question doesn't allow us to take away:
Maria Vásquez has a wide range of experience, having had
worked intechnical, production, and marketing positions.
There is only one provided option that fits the provided blank.
